Does my reputation score affect the amount my vote is worth?
No.
Plus some corrections on the following in light of the article published:
Why won’t Steem Dollars become inflated?
Because they work differently from normal STEEM tokens that can get inflated a lot. Steem Dollars are backed by the issuance of STEEM tokens. When the value of the STEEM token goes down, more STEEM tokens are used to back the Steem Dollar. The Steem Dollar is ultimately unaffected by the inflation of Steem with one exception: If the price of Steem tends towards zero. In general the price of 1 USD is a target price and cannot be absolutely guaranteed under any circumstance. In particular there are a few unlikely "Black Swan" events, like Dollar Hyperinflation and STEEM going to zero that can affect the backing mechanism. Additionally, the number of Steem Dollars in circulation should not exceed 20% of STEEMs market capitalization for safety reasons. There have been some proposals to handle such a scenario in the following link: https://steemit.com/steemit/@dantheman/steem-dollars-have-limits
I thought that was the answer to the first question, but I couldn't find it explicitly stated anywhere. So thanks.
The FAQ needed a better explanation for the 2nd question, and I think you answer the question fairly here. It hits the salient points from that article by @dantheman