Steemit user feedback from a newbie

Ahoy!

So today was my first experience with Steemit. Is been awesome to see how things work. However, I thought it would be valuable to give some feedback on my experience so far. Here are some tidbits in bullet format:

1. The History view in my wallet does not seem to contain any details. This is while using the site on my iPhone. Not sure if that is the issue.
2. I would like to see where my up vote Steem Power has gone.
3. I am not sure if one receive and give Steem in set denominations? Can these be changed or not?
4. I'm sure I'll get it soon, but a summarised explanation of how Steem and Steem Dollars differ.

I will have a follow-up summarised post one I have the answers to the above.

Any comments to enlighten me on any of the above will be very much appreciated!

Have a STEEMing day! :)