You fail to mention the class of your main character, which is a crucial piece of information.

Also, it would help if you would avoid run on sentences and if you would put some spacing at logical points in your post; as is, your post is hard to read.

I guess i did forget to mention his class and just saying what it is in one post and nothing else would be a waste so i guess i could go into detail
He is a Dwarven Fighter and has
18/16 Srength
18 Dexterity slightly enhanced by his enchanted gloves
19 Constitution
8 Intelligence
5 Wisdom
And finally 11 Charisma
Generally i think he is a functional fighter and probably the strongest character in my party especially in comparison to my other fighters who get constantly hit.

What constitutes a "good" party or character is mostly subjective, at least in terms of whether or not you can win the game, and presumably kick arse along the way, with the chosen members.

You do have all your bases covered, by the looks of it. You've got both types of magic, along with some muscle and thieving abilities.

I'm a big fan of Jaheira, especially once her strength is upgraded with the ogre gauntlets (if you so choose).

I would add, however, that some extra magic is often nice for large enemy groups and/or tougher opponents. Spell buffing not only helps win tough battles, but it makes me feel more strategic when preparing. As for offensive spells, there is nothing quite like webbing (or some other disabling AoE spell) and fireballing large groups of bad guys. Great fun!

Khalid, Jaheira, Minsc, Dynaheir, and Imoen are the canon NPC party members for BG1. It has people that can fight on the front line (Khalid, Minsc, Jaheira), a thief (Imoen), an arcane caster (Dynaheir), and a divine caster (Jaheira). Your PC adds to the front line, which is also fine.

This party should be able to get you through the game.

Other notes:
-Thieves level a little faster than other classes, which is why Imoen is higher level.
-Dynaheir is probably the last one added to your party, so she may have a lower XP total. Also, Iirc mages tend to level a little slower.
-Check each character's AC. Lower AC values mean a character will tend to get hit less. Your PC has strong armor (ankheg armor is comparable to full plate mail) and a high dex (most of the front line oriented npc's don't have 18 dex); if he has a shield, then he probably has the best AC in your party. Also, be aware that certain kinds of armor have bonuses or penalties against certain kinds of attacks. Example 1: Unenchanted full plate mail provides an AC of 1, but it acts as AC -3 versus slashing and AC -2 versus missile and piercing attacks. Example 2: Unenchanted leather is AC 8, but it has a +2 penalty against slashing and piercing attacks, which means it offers no protection against piercing and slashing attacks.
-Mages can't use many kinds of equipment, in general. Find and scribe scrolls to add to their spellbook.
-Explore areas to find more equipment, find/complete more quests, fight more monsters, and thereby gain more power.

Where did you get that ankheg armor hmm? ;)

With the information you have given, I assume you are following some kind of walkthrough and have some basic D&D knowledge. Your team is perfectly fine and it will get better soon. You may try giving the dexterity bracers to Minsc which will turn him to an amazing archer and a frontliner (with bonus AC). I mean you can do that if your main DEX is not too bad.

Other than that you will be fine. You survived the worst part (low levels) already.

Your party is pretty low level for fighting Tazok, explore some other areas first and return when you're more powerful.
You could replace one of you warriors with a cleric for added flexibility to make the game a little easier but it's beatable with any combination.

You party is reasonably good. The main problem is that all your characters are low level for Bandit's camp and Tazok (which is Chapter 4 is believe). Usually, Chapter 3 should be used to explore the world, do subquest and gain valuable experience. By exploring the world you will also gain better items. For example Bassilus (near Beregost) drops hammer +2, Grey Wolf (Prism quest) drops long sword +2. There are some very nice items in the cave located in one of the area at the coast. Also, by exploring you will earn money and be able to purchase some nice items from Thalantyr as well as afford Arrows +1 or, even better, +2.

As someone suggested, get Minsc Braces of Dexterity, get him enchanted long bow (you can get one in Feldopost Inn) and he will become a great archer. Once Dynaheir gets to level 3 she should be able to learn spells such as horror which is extremely good.

Imoen with short bow +1 or +2 can also be a decent support for the main party. So get her a good bow, Arrows +1 and she will become a useful addition to your party.

Oh, and last thing! Use potions to boost your stats before the heavy fights. Strength potions, dexterity potions are quite common and can help tremendously in some fights.

Personally I never play with in-game NPCs, I always design a full party of six. It is definitely a more "power-gaming" option as you don't have to put up with the bad stats of the NPCs, who often have terrible rolls like 14 Dex (which gets you nothing).

That said, if you find something that seems to hard, absolutely just go somewhere else. It's a huge game and there are many areas to explore. You will level up your characters a bit and get better gear as well. I highly recommend mikesrpgcenter.com as a resource for finding any gear you're looking for or just seeing what's available. Proficiencies are more generalized in BG1 than BG2 so it's not as big of a deal, but it's still nice to know what weapons are available so your can plan out your party.

You didn't say whether you're playing BG: EE or not, so I'm not sure if you had half-orc as an option but they make amazing fighters. If not, next time you roll a fighter try to get 18/91 or above strength (I believe that's the highest breakpoint until 18/00 which takes a lot of time and luck since it is literally 1 in 100). As a fighter you don't really need the "mental stats" (Int, Wis, Cha) but that exceptional strength number matters a lot.

Good luck!

This is actually something that puzzles me. Why did they switch from more general proficiences to more specific ones, and in doing so, exacerbate the issues with the proficiency system?

The reason I don't like the proficiency system is that it requires you to make semi-permanent decisions at the start of the game, but the information you need to make an informed decision isn't present until later in the game. (For example, could you explain, without any spoilers or information not contained in the manual, why (from a gameplay standpoint) someone would (not) take Katanas over Long Swords, or Flails over Maces?)

(I also don't like the fact that you are essentially stuck with your starting stats forever.)

For the sake of a challenge...?

:/

That doesn't fix the problem. If you want to challenge yourself by taking the less favorable choice, you still need to know which choice is better.

If that is a "functional" fighter, then I wonder how strong one must be to be considered good or great. Apart from being more lucky with the 18 strength roll, that is an incredibly strong fighter, and being Dwarven, he's even stronger than many others for the task at hand.

At some point through the game, you will get a tome that can add 1 point to strength, so if you use that on your fighter, he'll hit viciously hard at strength 19.

The party is more than fine too, it's what I used my first time through the game. You have all the bases covered, and it's a fairly strong lot. You may want to focus more on side quests, though, so you can level up a bit more before tackling more or the main storyline. There are a lot of areas to explore in BG1.

25 in each stat. Go big or go home.

25? That's way too low. If you want to be effective, you need to raise your stats into the millions at least. Otherwise, there is *no way* you could defeat Baal, who is at least level 4000.

Anyway, in Baldur's Gate 2's expansion, there is a spell which has a chance of being able to actually give you 25 in all stats. The effect is only temporary, but temporary is still long enough to go through your stash of scrolls and scribe them all (with 25 Intelligence, scribing a scroll can't fail). By the way, did you know that in BG2's tutorial, Xan has 25 Intelligence?