time limit on post and backing out of post

I notice i missed spelt on one of my post but when i tried to change it it told me the editting a post time limit was up and i can not fix it. i dont think post should have a time limit on them, because some people have spell correct which can lead up to drama or miss understanding. and when i go into a post like comments there no back arrow i cant exit it so i have to do the back arrow on the site page which start me over on the home screen making me miss out on other peoples posts, oh and one thing could u do like a save post in case some or i see some thing n want to look back it later if so that be awesome. and thank you so much for the site i really love it <3