You certainly haven't characterized this person as a best friend (usually the case when you're asked to be a MOH) -- so if you are not very close to her, I can see why this whole thing is extra irritating.
Certainly, one person stuck throwing a bridal shower for 50 can be tough financially-- sorry you are in that situation (but amazed you can do it for $200 - so congrats on that) . And it's definitely overbearing and insensitive -- for her to ask you to throw both the shower and the bachelorette party ! Good for you for putting you foot down there
And yes, it is a flurry of activities in a brief amount of time , and overkill to add the engagement party at the end (I would not want to devote that much time in two months to one couple -- unless it were my best, best friend).
That being said -- I wouldn't be so up in arms about there not being a rehearsal dinner (I'd actually be relieved I didn't have to attend another event with this crew!)
She certainly sounds ungracious and ungrateful in how you've described her, but focusing on whether she's getting you a gift or not, just seems sort of petty.
Bottom line -- doesn't sound as if you're being appreciated, which isn't right and never feels good. But expecting to be "repaid" with a dinner and gift, is viewing this more like a business transaction than a friend's event
Again -- don't know what your relationship is with this person -- but I might reevaluate after the wedding as she doesn't sound very considerate.