Task Manager Performance Stats questions + Bonus Question

Hey guys, I was testing the performance of a game i'm working on and the task manager stats were bizarre. Can anyone explain why this is happening (More info on task manager stats in questions below).

1. Can someone tell me why unity is using 100% of my Gpu? I read from forums long ago that Unity uses whatever is available, is this still true?

2. My Cpu usage hovers at 10% without the game running, about 70% in my Hub Area, and 70%-90% in game, is this normal?

3. When running my game it uses 1.8 GB of memory this seems like a TON, what could be causing this? (Btw my system is only using about 6GB out of the 16GB in my computer).

Bonus Question
1. My game is randomly crashing but not crashing with unity's crash report system it just stops responding then closes. Could this be a ram issue or something else?