Maybe something you could add, remove that big blue bar or resize it to make it smaller when all three buttons are removed.
EDIT: I also noticed it has problems opening big files.
I tried to open a 112 MB text file with 194519 prime numbers in it, and it took about 5 mins to open and it the memory usage maxed out at 395 MB.
After that when minimizing it to systray, the memory spiked up to 700 MB!!, and it gets gradually higher somehow
EDIT: Added screenshot