On queries:
Wow, I have to say I would never send a query out first to a 'low on my list' agent. While you are not obligated to go with them, if they do say 'ok', then you have set up a difficult situation. Do you now say 'nevermind' and not only turn your back on a professional in the field (it is a close-knit community), but perhaps (you don't know yet) the only person who wants the book? Or do you go with them and never get a chance to try your first choice?
Otherwise, yes wait on the query. You need to be ready, and I seem to recall you mentioning that the first five pages were polished. If your query comes back positive, they may ask for the whole thing or they may ask only for the first 2-5 chapters, but they are unlikely to only ask for a few pages.
On critique groups:
Yeah, critique groups are tough. There are many more bad writers out there than not. That said, if you take a look at the writing the other folks in the group are doing, you can get a good idea of whether it is worth investing your time. I know I was on writerscafe.org for a bit, and just decided that I wasn't getting many useful critiques. I was also reading so much really bad work it was ridiculous, and I felt like to do myself justice I had to give a good critique - but bad writing is a lot of work to do that with. I just gave it up.
As mentioned, groups can be of wide ranges - not just in skill and craft but also in life experience, age, etc. But you don't know anything at all about your local groups until you try. (Or until you set one up yourself. From what I've heard, Barnes & Noble is very receptive to hosting and advertising local writer's groups.)