I'm wanting to start a new game from the beginning and I'm going to play a Half Elf Thief. I don't like any of the Thief companions from BG2 as my main thief.

I'm going to build it to duel wield and use bows. I never bother using stealth or backstabs (mainly because I always forget or can never be bothered). The skills I will focus on most are picking locks and finding/disarming traps

I'm looking for a fun, strong and easy to play thief class, or even fighter/thief. What would you all recommend to take through both games?

The Swashbuckler could be a good choice. Its main downside is no backstab multiplier, which should not matter since you don't want to bother with backstabs. Its class perks boost general combat capability, though it still won't get the extra attacks-per-round that a fighter gets.

If you choose a Fighter/Thief, then your choices are made for you, since multi-class characters cannot choose a kit.

if you arn't going to use traps then a Fighter / thief or Mage / thief will be good options for Elf but Bounty Hunter is my pick as 'best' kit with its toss-a-trap skill you can walk back a few steps then give them a trap in the face

Fighter/mage/thief is a fun option. Just as long as you don't mind waiting extra long for your first level up.

That's my choice when I'm going to solo.

I assume you are referring to the difficulty of giving a pure class Thief (or its kits) an item with Protects against critical hits, since almost all such items are helms and a Thief without Use Any Item cannot wear most helms. Yes, a Fighter/Thief would overcome that, by virtue of its Fighter side allowing use of a helm. However, the inability to wear helms is a problem for all Thief kits, not unique to the Swashbuckler. However, even a character who is susceptible to critical hits will not "die instantly" solely due to receiving a critical hit. Rather, they will take double damage, which while significant, is not guaranteed to be fatal.

Prior to the Enhanced Edition, some Ioun stones offer Protects against critical hits and can be worn by thieves, even without Use Any Item.

Yes, that is why I didn't say all critical hits kill. The swashbuckler is advertised as a good melee person, and that is what I do not agree with. A dragon can for sure, maybe some golems and giants also without a protection item or two. Problem is that by the time the swashbuckler can wear these items a fighter could have a flail in each hand hitting 5 times per round just because they have the weapon points and levels.

The Swashbuckler is not as good a melee fighter as a pure Fighter, but it is better at melee than the other Thief kits. If OP wants a thief (which was stated as a goal in the opening post), and does not care about backstabs, then Swashbuckler is the best thief for OP to use, because its only downside relative to other Thief kits does not apply to OP's play style. If OP wants to play a melee combatant and does not care about thief skills at all, then yes, a figher would be a better choice than a thief. That is not what OP requested.

The phrasing you can die instantly is, in my opinion, confusing here, because any character can die instantly if hit hard enough while sufficiently low on hit points. Any melee character who wants to avoid instant death is obliged to always have enough hit points that a worst-case damage roll from the enemy will not exceed the character's health. Lack of Protects against critical hits merely raises that threshold from the enemy's normal max damage to twice the enemy's normal max damage. Most people won't be meta-gaming enough to know exactly what the maximum damage threshold is, so in practice this just means keeping the character as healthy as possible.

You say that a high level fighter could dual-wield Flails and achieve 5 attacks per round. I assume from the lack of disclaimer that you think this rate would be sustained indefinitely, which rules out the use of Haste or similar temporary effects. How would you achieve 5 attacks per round indefinitely? As I understand it, you will get:
- 1 Main hand attack
- +1 Main hand attack for being a Fighter of level 13 or higher
- +1 Main hand attack for Grandmastery in your main weapon's type
- 1 Off-hand attack

That only gets you to 4 attacks. To get a fifth attack, one of the two hands needs to wield an APR-increasing weapon. I am only aware of 3 weapons which do that, and none of them are Flails. One of them is even restricted to Monks (and Thieves with Use Any Item).

https://baldursgate.fandom.com/wiki/Belm (Scimitar)
https://baldursgate.fandom.com/wiki/Kundane (Short sword)
https://baldursgate.fandom.com/wiki/Ninjat%C5%8D_of_the_Scarlet_Brotherhood (Scimitar; restricted to Monks)

So you're saying that thieves aren't as good at fighting as fighters? Provocative!

The idea that a thief needs protection from critical hits is debatable but the suggestion that helmets are the only way to get protection from critical hits is wrong

For myself, whichever method of providing the crit protection, I'd rather use that slot for something else. There's a lot of cool stuff to adorn your mc with.

The other half of the swashbucklers problem is that they have a much lower capacity to HP damage than any type of fighter at only 6 health vs fighters 10 and only half of the constitution bonus. You will probably want to play without the double damage option if you have swashbuckler as main character.

Give Bounty Hunter a go, those traps are insane.

In the end I went with a halfling fighter/thief but thank you for the suggestion anyway