it is hard to hack your Email account but not impossible if the hacker isn't lazy he will do it ,now face book accounts i only know of 7 ways to hack that and i think there is still a hell lot more of ways,and also yes they can hack your account after you deactivate it but it is harder then when its activated.
I am not gonna tell you the ways i know of hacking but i am gonna tell you some ways , because there is no way you can prevent it, the hacker will not fail his hacking ! this is what you can do..
1:make a new Email (you cant make a new fb account with the same Email) and account with a totally different name and add FRIENDS not just people you know.
2:try not to do so much activity on your account (for a very important reason) i cannot tell you why.
3:make an anti hacker password such as something that will confuse the binary form of hacking,like something that doesn't make any sense at all or put a link of something, i can tell you why: it will be exhausting for the hacker to find out the link.
4:do not EVER accept links from anyone unless you are completely sure its safe.
5:program you computer to not accept so many cookies and use more frequently incognito browsing instead of normal browsing.
6:do not try hacking it is just mindless.why? because you will end up hacking yourself.
7:never turn your firewalls of and download or buy an anti virus.why? because the hacker can send very harmful viruses.
8:change your computers IP address.
9:do not go around places sayin your a hacker.why? it will make real hackers want to hack the living $h!T out of not just your face book ALSO your computer! an example of how powerful a hacker is do ctrl u THEY CAN track your browsing location
10:the hacker can make an exact copy of your accounts so after you change everything tell all your FRIENDS thats not you (by Friends i refer to people you really trust)
and that is all you will need bro XD