That is not quite true. The thing is a 100% reduces your current voting power by 2% so to keep it at your example with the 17000 SP and a voting power of 50% that would mean if you cast 1 vote at 100% your voting power after that vote is 49% (50%-(50%*2%). So basically a full vote at 50% voting power "costs" only 1% which added up will once more be the $10 per day. So as you can see you are able to distribute the same amount each day only the max value and the number of votes changes.
Edit: Should have read the comments first as I see now you guys already figured it out ... ;)
Yep that is correct
Ah yeah and to your second question:
No, still all the same only new name (although I really do not understand the reason why they changed voting power to mana, since voting power gives a better understanding of what it actually is)