Drosselbusch: Yeah, but this is not a passive buff, just a spell with low healing effect. Nothing important. And a paladin has to gain more EXP for a level up compared to a fighter.
I believe you're possibly referring to my thread that disproved the existence of the Paladin's innate protection aura, if you're speaking of the thread that ended up being a wall of text that used binomial hypothesis calculators and Displacer Beasts, so I thought I'd chime in (several months too late, but better late than never!)
To answer your first question, the HP overflow bug only affects EOB1 IIRC. It's actually pretty easy for a 19 CON Dwarf to break himself by gaining too much HP, even without save-scumming! In EOB2/3 you don't have to worry about it.
stryx is correct that Lay on Hands is the only benefit to Paladins over Fighters. It's often quite useful, because the amount it heals is 100% consistent—the Paladin's level, times two. No more, no less. Otherwise, Paladins are simply Fighters that level up more slowly.
But in my last few playthroughs through the trilogy I've actually changed my mind about the best party. Instead of a Paladin and a Fighter in my front line, I've come to believe a Fighter/Cleric is the best choice alongside a pure Fighter. Half-Elves are capped at Lv17 in both classes, far above what you'd ever reach in EOB3 without cheating, but Dwarves are just as effective if you prefer their higher CON. Their max Cleric level is 13, which should still be no problem (I usually finish EOB3 at about Lv11 or 12 with my single-class characters).
Fighter and Cleric are both classes that level up reasonably quickly, so in my experience, I've only ever been one level behind what a Paladin would be (and thus only one point of THAC0 behind). Meanwhile, my single-class Cleric in the back row doesn't have to split her spells up between heals and buffs, and we know how important buffs are in the trilogy. At spell level one, my backrow Cleric can memorize Bless exclusively, while my Fighter/Cleric in front can spend all his slots on Cure Light Wounds. At spell level two, my Fighter/Cleric can memorize many casts of Flame Blade and wield it with his superior Fighter THAC0!
At spell level three, the F/C can memorize one cast of Create Food, leaving the backrow cleric free to spend that slot on another all-important Prayer cast. And both can memorize 1-2 casts of Remove Paralysis; with two members that can cast this spell, as long as one isn't paralyzed, you'll be able to remove paralysis. Spell level four: the F/C devotes all slots to Cure Serious, leaving the backrow Cleric able to spend every slot on the Protection from Evil 10' party buff.
Even better, since the F/C is mostly going to be casting heals outside of combat, you can throw away his Holy Symbol and simply have him borrow your backrow Cleric's symbol temporarily to cast heals. You don't even have to open the inventory screen.
Taking a F/C in place of the Paladin is best for players that _don't_ want to run with a party of six and share EXP with NPCs. The F/C makes your party more self-sufficient, so you don't need Ileria (and his/her terrible Wisdom) in EOB1, or Shorn or Tanglor in EOB2. This synergizes well with a Fighter/Thief in the other front slot, making for a 100% self-sufficient party (Fighter/Cleric, Fighter/Thief, Cleric, Mage) that can experience all content without keeping a single NPC other than unique situations like escorting an NPC in EOB1 briefly to get the Wand of Silvias.
For players who want to recruit NPCs whenever they can, I wouldn't recommend this party. The EXP really dries up when your multi-class front-liners are getting 1/12th of the total (divided by 6 NPCs and then again by 2 classes). Every time the game divides the EXP, it discards the modulo/remainder, which can really add up if there are 6 party members instead of 4. I'd still recommend the classic Pally/Fighter/Cleric/Mage party for players who keep a full party (though you wouldn't be losing too much by taking a second pure Fighter instead of the Paladin).
(edit: I would still take Slicer in EOB1, btw. You'll find other +3 short swords in the sequels but nothing better, so it's effectively an EOB3-endgame-tier weapon, and monsters that require magic weapons in order to hit them start showing up early in EOB2. The Ring of Wizardry sounds nice, but you can still get other copies in the sequels, and in practice Mages are better off memorizing buffs like Haste and, when nuke spells are needed, using Wands to cast them instead. There are so many wands in EOB1 alone that they end up causing inventory management issues if you're overly cautious with them and don't use them enough!)
