hi guys! just got back home, thanks for all of the useful suggestions so far! to answer/confirm some of the questions, it's a hollowtech ii bb, sorry i forgot to mention that in the beginning.
The frame is steel (28.6mm is the size of the clamp on FD). As far as what gears were sort of the most usable, definitely the inside 2 chainrings worked pretty well, using the largest (48t) there was quite a bit of chatter once i got a couple/few cogs into the cassette. I rode it for a minute or two fully crossed on flat ground and it definitely didn't like it.
It's difficult to qualify what 'good enough' means, well really - what it meant at the time. I've only ridden it about 3 miles on a flat stretch of road near my house to work out kinks after assembly. I then promptly left the coast for a few days and just now returned a little bit ago. i could shift between all gears smoothly but there was lots of noise when i started to get to the inside of the cassette (11-34), i don't think it's something that's well configured for long-term use right now.
I just went and looked at it again to make sure i remembering it correctly. The chainline right now should be at 47.5mm given the spacer arrangement i've got (just a single 2.5mm on the drive-side). The chain is about as perfectly straight (parallel to the wheel) as it can be when on the big chainring and the smallest cog.
I think what i'm probably looking at is swapping out this deore crankset for a Sugino configured with the same chainrings. I've never had to fit a bottom bracket spindle properly before although i called a shop near me, explained the situation and they told me that a 110 was most likely what i would need.
My frame is similar in measurement to a 62cm Surly LHT and i keep seeing people post of positive results with a LHT frame, XD600 triple crank and a 110mm spindle.
UPDATE: Forgot to mention my intended use for the bike! I'm going to be primarily on the big (48t) chainring using the middle every so often and the granny for the hills when i'm loaded (my panniers
)) Most likely - flat rolling hills and some steep (but slow) uphill.