I think you all know my now, good enough to say that I like to play a role that does consist of different, of other thankls than only fighting, too.
If I accept a quest from any NPC I do this not for the prospect of future fight ("Oh ! Great ! Another enymy to whack down 111 This is sooooooo much FUN !!!!!") but for the social interaction this quest provides to me. I do an NPC a favour … and want to get repayed for it, for example.
This is clearly rooted in my love for adventure games.
NotR actually significantly expands upon game´s social aspects. It adds
a lot of new characters to interact with, as well as adds new dialogues to existing ones. Among other things, this makes the whole G1 + G2 narrative much better as a whole because NotR adds quite a lot of ties to the first game.
One aspect that I liked in G1 and found rather lacking in vanilla G2 was the opportunity to tackle some parts of the game along with a companion. There were few such instances in vanilla, most notably in chapter 4, but NotR adds quite a few more to chapters before which results in a more diversified gameplay and more sociable feel. There´s even one moment when you can have 5 dudes under your command.
Also, there´s a relatively long "detective" quest in the addon which requires next to none combat.
And you can still feel as a jack-of-many-trades in NotR. You probably shouldn´t try to boost all your combat abilities at once, sure, but you can still easily learn most of non-combat ones, like pickpocketing, hunting, forging etc. Plus, NotR adds new non-combat skills - ability to understand language of the builders (which you can use to read skill/attribute boosting stone tablets), you can summon a Wisp which can find some treasures for you (not really all that useful though) and you can learn mining ore which can give you quite a nice money boost.
And, every character can use magic scrolls which adds quite a lot of new variety and tactical possibilities (this is actually the reason why I think mage characters drew a bit of the short straw in G2 when it comes to diversity - there should be some spells only usable by them, at least NotR tries to remedy this somewhat with Beliar runes).
The expansion doesn´t change the overall combat/non-combat gameplay ratio.
Also, and that goes for both vanilla and NotR, you certainly aren´t always expected to whack your way through. For example, you´re not really forced, or even expected, to kill everything in chapter 2. The brilliance of the whole second chapter´s design lies in that it forces player to find creative ways how to avoid galore of potentially very lethal combat encounters. With NotR however, you can have some fun whacking orcs with Diego and if you´re thorough even get a Nostalgia bonus, heh. Still, the whole chapter is really an exercise in survival, not in hack´n´slash - and this goes, to maybe a bit lesser extent, for the rest of the game as well.
The game´s weak points were always the hack´n´slashy chapter 4 (though most of combat can be avoided there as well), sketchy chapter 5 and unimaginative and rushed chapter 6. If you play with NotR, these weaker chapters at least become comparatively smaller part of the whole game.
Basically, my point is, your reasons for not playing with NotR are actually more valid for not playing the game without it.
Obviously, my advice would be to give Gothic Gold a try one day, maybe just don´t play a mage. I´m quite sure that you´d be able to get a reasonably jack-of-all-trades-y experience if you´ll play either palladin or mercenary.