Are we measuring wallets here?

I recently deposited more Steem. The entire concept of Steem Power, Steem Dollars and Steem eludes me. I understand the core definitions of what they are in relation to one another, but I watched $188 balance in my wallet rise to $430 in a matter of days, with minimal contribution on my end. During that time I wrote 200 comments across posts and upvoted regularly and while I received multiple SP and SBD rewards I would be surprised if collectively they were worth more than $20. If the rise was mostly due to the rise in STEEM price, then it means I would have been better off depositing all of the crypto I have on Poloniex onto Steemit as SP. I even have Steem on Poloniex. I can proudly say I understand about 80% of how Steemit works, but that final 20% involves confusion understanding...

1)How the conversion rate between STEEM and SP impacts powering down and the sustained value of deposits, and what role do MVESTS play in this?

2)If it's true that SBD is always held to a dollar with 10% annual interest, when the price of SBD rises to 1.7 to the dollar, should I exchange it for STEEM before it's periodically pulled back to the price of a dollar and how do I know when that will happen.

3)I know the rules about upvoting and not upvoting more than 20 times a day, and I know I can track my upvoting power on steemd, but as a principle I always upvote comments on my posts regardless of my power but still want to upvote posts for curation points. I read that when you upvote more than 20 times it statrs to reduce the value of your rewards. I put a lot of thoughts into my comments and have received valuable upvotes for them but notice a significant fluctuations in my rewards that directly correlate between when I am asleep verses awake as in higher during periods when I was asleep 7 days ago and lower when I was awake 7 days ago. I suspect this upvoting policy has something to do with it, but I am not sure.