Baldur’s Gate: Enhanced Edition Item List

The new companions correspond to some of the new class choices that are available. The Blackguard kit for Paladin, the Monk (base class, but implemented interally as a Thief variant), and Wild Mage kit for the Wizard. There are also the Sorceror and Barbarian classes, and a few other kits that BG1 didn't have.

There are some changes to the user-interface to scale it to larger resolutions, and mouse-wheel or pinch can zoom in or out the scaling.

Some changes that will also be evident from comparing Baldur's Gate 2 to Baldur's Gate, because they are doing the same as the Tutu mods and running a fixed-up version of the Baldur's Gate 2 version of the Infinity Engine to run the original game: two items of note here, aside from the above

• New races
• Dual-wielding

I believe the team wanted to implement more new races but weren't allowed to by Atari or Wizards (not sure whom), but you get Half-Orc addition at least.

Various mods out there fixed issues with the original game. A short list from this forum post explains which ones are no longer needed:

• ToBEx fixes game engine bugs by modifying the executable: To be honest, I'm having trouble weeding out what here is just hacks/mods and what's actually been fixed. I believe a scroll-bar on the kit selection UI means you can add more kits to the game without not being able to select the last added ones (something modders had to deal with by removing other kits).
• BG1 Fixpack
• BG2 Fixpack: Fixes to descriptions, sounds, barbarian/berserker rage/enrage, and a ton more.
• Baldurdash fixes for BG1
• Baldurdash fixes for BG2, where it applies to the engine/rules/etc and not BG2 specific content
• Dudleyville fixed over 700 things. Some of which are fixes to errors in NPCs (illegal proficiencies for classes, for example), spells
• BGT or its fixes
• Widescreen mod
• One Pixel Productions list of changes are:
  • BG1 Paperdoll and inventory item ports, except for potions.
  • BG1 Potion Graphics
  • BG1-style Flaming Swords
  • Flaming Short Swords (with item and mod item patches)
  • New Paperdolls (human, half-orc, elven, halfling, dwarf)
  • Legacy Shields - Bucklers (D1)
  • Legacy Shields - Small Shields (D2)
  • Legacy Shields - Medium Shields (D3)
  • Colourable Quarterstaves (with item patches)

Edit: I just realized there's one actual removal-- there is no longer EAX support for position audio and reverb. It's a little disappointing but not a deal-breaker, IMO.

Honestly, there's very little reason to play a pure thief in BG 1. Between the numerous thief party members available (it's the most common NPC class by an order of magnitude), and the relatively low number of points needed in most thieving skills to be effective (even further reduced by the ready availability of thieving potions), you just don't need more than 8 or 9 levels in the class. BG2 made up for this by introducing High Level Abilities, from which Thieves draw the best pool by far, but this isn't a factor in the BG1 EE (at least not yet), so I wouldn't build a character with an eye towards BG2.

That said, you have a few strong options:

In general, you're better off dual classing into thief rather than out of it. A Kensai dual classed into Thief can be a very strong melee combatant, for example. If you do intend to start as a thief at level one, then using the Swashbuckler kit is a very good idea - you give up the Sneak Attack ability but the +1 AC, hit, and Damage /5 levels, plus access to weapon specialization and full two weapon fighting means that Swashbucklers can hold their own in a toe to toe fight. More importantly, Swashbucklers have a full compliment of thief skill points, so even if you're only starting with 5 levels before a swap, you don't really lose much.

The other very viable option is to go full into traps, possibly (but not necessarily) using the Bounty Hunter kit. If Baldur's Gate is a game built around the identification and exploitation of cheesy tactics, traps are, by far the cheesiest. They're also wildly effective - if you invest in the skill. They do solid damage, from a BH they'll offer a variety of useful debuffs, and they're relatively easy to manage.

And finally, as you note, there is always the classic Elf F/M/T option, which will be able to do literally everything. The slower leveling is just not a sufficient hindrance.