I have found that when you receive an item that is bound to you immediately (not 'binds when equipped') you can use the crystals installed on the item, even if the item would normally be restricted.
However, if you remove the crystal you won't be able to re-install it.
You gained a level with regular XP and a level with rested XP. Had you not had the rested xp you would have only leveled once.
Correct, also explains why you still had green xp into level 14.
I know the cap is one level above your current level. So, for example, if you needed 100,000xp (total, not remaining) to reach your next level, you could bank 100,000xp rested.
The option "Show Item Detail Tooltips" accomplishes this. TBH I have all the options under "Tooltip" selected. Knowledge is power!
Again I edited my original post to reflect this.
@Randomness thanks for the reminder about the different options
There is an option in the game settings that allows you to compare new equipment to both your current gear and your companions. I'm loading the game right now for more specific directions.
EDIT:
Game menu -> Preferances -> User Interface -> Tooltips section (You may have to scroll down to see this)
Enabling the setting "Enable Comparative Tooltips" will only show your currently equipped gear.
This setting has to be selected before companion or mod stats will show.
Enabling the setting "Enable Stat Summarization in Item Tooltips" will show the differences between the items.
Enabling the setting "Enable Companion Comparative Tooltips" will show your companions equipped gear.
Enabling the setting "Show Detailed Item Tooltips" will show specific information about item modification in orange gear.