Samsung Galaxy S4 — Gallery is sluggish, lagging, or crashes phone - so many weird glitches with my Samsung phone

Hi,
new to this forum.
Whenever I open the "Gallery" app that comes with the Samsung phone, it either lags - takes about 4-5 seconds to load. Or it might crash, and say "unfortunately Gallery has to close"

Also, when I delete photos from the gallery app, sometimes they re-appear a few days later. Same thing with Google Photos as well. I'm not sure if it's an SD card issue, I just bought a new 32GB SD card and it seems to be saving the photos easily however when I try to delete a photo it sometimes comes back a few hours later or days later.
My main question is: is this a common thing with Samsung phones? if I buy the new Samsung galaxy S6 phone, will I be having the same issues?

Another problem, whenever the phone is locked, it sometimes doesn't show the numbers to put in the pin number. It comes up as little blocks instead of digits.

Another problem I used to have, but doesn't come up so much anymore - whenever I open the "Contacts" app, it just crashes for no reason and says "unfortunately contacts has to close."

I'm almost ready to switch to HTC or back to the iPhone.
My Samsung galaxy S4 has had SO MANY weird quirks, bugs, issues, glitches, etc.

Has anybody else experienced weird glitches with this particular phone? is it mostly an S4 thing, or does the S5 and S6 have less glitches?

thanks