there was no spell bonus for high int? maybe I'm confusing that with 3rd edition. Anyway, scroll transcription seems to always work regardless of int in EOB. However the point remains that the spells aren't too good. If you play like defeating an enemy, then resting, defeating the next one, rest, repeat, then yes, you can percieve damage spells as usefull, but the problem is always the lack of ammo if you so will. Cast a decent offensive spell once or twice and then the mage is empty. Later AOE Spells are decent, but they are just too few. That said, there's those rings of wizardy, which give you more spellslots and wands which have more ammo, but you can harvest these bonusses with a classcombined mage as well.
So, if you can accept a weakspot in your party, which is likely to die once you trigger a trap, get flanked or get hit by AOE, then yes, you can put a mage in the backrow. I wouldn't recommend it, though.

In the beginning of the game the front row characters do most of the fighting, that's true. But even then an occasional magic missile is uselful against a kobold, a spider or a kenku every now an then. And it doesn't take long for your single class mage to have access to spells of the third level like fireball, lightning bolt and haste. That's when he is beginning to turn the tide of battle and from there on it's only getting better.

An elven mage in EOB starts at level 3 and can have up to 18 hp. That should suffice for the occasional pitfall. And till the game starts throwing AOE damage against the party (What is the first instance of that happening in EOB? The evil mage with his ice storm spell? He usually does more damage that way to himself than to my party.), he should have a few more levels under his belt. Of course you could insist on creating a mage with only 1 hp, but that would be your decision.

I created a mage with an int of 9 (which is the lowest possible amount) and tried to scribe a few spells and it worked every time. So my guess would be that in EOB int doesn't seem affect the scribing of spells. Looks like they didn't implement that rule.

Soo I've played through EOB1 several times now, tried different approaches and I've got to say, thanks to the increadably good loot, the game is really easy no matter how you twist and turn it. Having a good melee offensive is key, and most attack you can dodge. Now the only thing that can resonably hurt you is when your character get paralyzed... or even worse, in Darkmoon those bees... paralyze you and poison you. Damn beasts.
Now pretty much the only way to go against that is having the cleric cast neutralize poison and remove paralyzisis, except, he can do that only so many times. So multiple clerics are actually a good idea.
My current team consits of handmade Elf Ranger and Human Paladin in front row and Gnome Cleric/Thief and Half-Elf Cleric/Mage. The middle row consits of npcs, Clerics and/or Fighters, combined and uncombined.
Runs increadably smooth so far.

When my front characters become poisoned my cleric casts slow poison on them and I let them stay poisoned, till we have left the area. EOB2 also throws a truckload of cure poison scrolls and potions at you, so that my cleric never had to bother memorizing that spell.

When it comes to paralyzing I always found those mantis to be much more annoying than wasps. But luckily the effect wears off, when you find a safe spot and rest for an hour. So even if my front row has been paralyzed and my cleric has run out of remove paralysis spells, my mage can easily dispose of the monsters, we retreat a few steps and rest for an hour.

In EOB1 slow poison is a good idea. In 2 the slowed poison gets overwritten with another poison that isn't slow.

Mages always seem more of a support role to me in EOTB rather than a powerhouse, fighters/front warriors always seemed more of the damage focused classes. Not that mages are bad- far frorm it: 3rd level Haste made your party a powerhouse compounded with two dual wielding front warriors taking full advantage of it. 4th level Stone Skin in EOTB I gave your party the def overload that Haste did to your offense- extra helpful when fighting the bugs as i dont think they could stun you while stone skin was still in effect.

In EOTB II you lose stoneskin as it was too overpowered but you will get Imp. Invisibility which could function similarly- Cast it on your two front warriors and incoming damage would be split up among front and middle characters. This was great as invisible characters were harder to hit and middle characters could dual wield shields getting a high def boost and you suddenly find yourself with a battle row of front dual wielding damage output, a shield wall battle row, and your support casters in the back row

Need that damage output, the level 3 lighting spell did massive damage to targets in a row without risk of backfire, then at level 5 you could get Cone of Cold which was another lovely non backfiring aoe spell. Improved Identify and Remove curse are always "handy" to have.

For frailty concerns, EOTB I didnt subject backrow characters to danger nearly as much as EOTB II does which gives your mage time to level up and get some exp. Give the mage a featherfall ring and pits pose no danger. By the time game two comes around your cleric should be close or already have revive so as long as your mage isnt an elf you can always revive back to life.

And even if your mage is an elf, you still get three shots at resurrection in EOB2, regardless of race. You might need two of those for Amber and San-Raal, though.

I think you get SIX shots in total... the ressurrection shrine is doubled. Depending on which teleport you take on your way out, it takes you to the other shrine. It would make sense that each of them has different counter (and I just checked the cluebook and it agrees with me - "7) [...] each holy symbol resurrects three characters[...]". I never had to try that though, I usually just reload when some of my chars die.

No, the second ankh is already depleted when you start the game.

You can see it here https://www.youtube.com/watch?v=1AK3Wg5c8RQ from 3:11 to 3:41

Interesting, I walked around so many times and it never occured to me to actually try both shrines. Or I did try and than forgot over the years. Sorry for the confusion, and thanks for the correction.

I've beaten EOB trilogy at least 3 times, probably 5+ times EOB and EOB2. I've always done:

Paladin Human
Half Elf Fighter/Thief
Half-Elf Cleric/Mage x 2

I dont get a 5th or 6th characters till EOB3, not even the npcs because they slower level progress. Fireball, Haste, Improved Invisibility, Bless, Prayer and Protection from Evil 10 will be cast 90% of the time.