Is this a question? If so the answer is ....any of mine;-)

As for the weekend ride: What is the flatland ride? Are you riding to the start?? I have a commitment but still working out the details. Might be a bunch of family at my house for fathers day which takes 2 days to prepare for. Not set in stone. Will post when I know more.

GB:
monument X2, easy but long
Charm and Grace: ( I was going to ask if this was our last ride but then it FINALLY dawned on me that charm= Balto and grace= havre de grace, no rocket scientist here) moderate but even longer
On Again off again hardest BUT I only rode 20 miles of it and there were 2 pink jerseys at the lead. From what I heard the pace did drop off eventually.

I think what makes a ride harder for me is not just climbing but the pace. When I spin at my speed I can last a long time in the saddle but when I ride in a group I try to match others pace(w/in reason) and I hit the wall sooner. On the C&G ride I rode the first 60 miles @ 15.4 which is my speed for a 60 mile ride. This felt fine but I felt tired at lunch. The final 60+ my speed dropped and I finished with a 13.9 for the day(thus 12.5 for the last 60+). So if you are really trying to analyze the difficulty of a ride you have to include pace. Granted we are responsible for our own pace BUT the definition of a race is:
2 guys on bikes heading in the same direction;-)
If you include distance, elevation gain and pace(plus temps and wind speed) you will turn biking into climbing. You don't want to go there:-) I think you described your rides well. Comparing one ride with another is the "BEST" way to describe a ride. You said that the C&G ride(compared to the M2M ride) was a little longer and more climbing but not a lot more climbing. That's what it was.
FWIW: I actually rate counties. Balto, Frederick and Washington counties tend to be moderate to hard; Carroll moderate; PG, AA(S. MD) easy to moderate(but mostly easy); eastern shore is easy.