Interesting, I'd only just seen this thread. I'm a long time user and fan of Boss/Roland stuff - GT-10b, GR-55, VB-99, GT-6b, ME-8b, BE-5b, zillions of Boss compacts. I would have also highly recommended the GT-1b for your needs and budget. Its basically a stripped down GT-10b and I think it actually has a few advantages sound wise over its bigger brother. Where it does fall down is the menu/GUI navigation which can be a bit confusing. I get around this by using the Boss Tone Studio software, which makes editing easy. Its also a little awkward to jump up and down multiple patches on the fly. I get round this by grouping patches together or adding a default patch either side of any more radical ones.
To comment on your summary above. 1/ It did take me some considerable tweaking to finally settle on a transparent default patch at something close to unity gain. The pre loaded patches all seemed very hot and so I started from scratch constantly bypassing the GT-1b to check. Once this was done I designed all my patches using the default patch as starting point and again bypassing and checking levels etc. repeatedly.
2/ The Chorus has a Low and High pass filter built in. If you set the The 'Lowcut' to anything above 125Hz you should retain all the low end as It'll be unprocessed. I actually find the Chorus in the GT-1b more extreme than either my CE-2b or CEB-3. I mostly use it for a subtle wash though rather than full on sea-sick wobbliness.
I'd strongly advise to to spend some serious time getting to know the sound and capabilities of the unit before you dismiss it. Every multi effects I've ever used has its own idiosyncratic nature. There are usually some things that each multi does well its just a matter of learning how to use the unit and find the sweet spots. The GT-1b is a great multi and is a very powerful bit of kit, I've programmed (and use regularly) Everything form Face melting Fuzz patches, through gentle grind, some rudimentary synth patches, It has a brilliant OC-2 emulation, the T-wah is one of my faves (including boutique stuff and my Mu-Tron III), I've even managed Royal Blood type splits and crazy Hammond organ patches.
Stick with it , I'm sure it'll be accompanying you on a gig soon.