Hi there! I can only answer your first question, as I haven't had a glucose tolerance test.
When I first got on met in March of last year, the first week or so I was on it I had NO appetite what so ever. I wasn't sick to my stomach or anything like that, just the thought of food grossed me out. It just felt full even though I wasn't.
I was only one met for a month or so and then DH and I decided to wait another year to TTC so I got back on the pill. I just started the met again in January and I only had a day of feeling kind of gross. I also was very constipated the first 3 weeks or so I was on it. I never had the opposite problem, thank goodness, EXCEPT when I had lettuce one day.

FYI - no lettuce on met.
So in general my side effects were very mild and tolerable. Now that I've been on it for almost two months, I'm pretty much back to normal.