Yeah, editing is possible... but all previous versions remain accessible. There's a handy tool to check the revision history of edited steem posts: https://phist.steemdata.com/
I don't know of any single source that would explain the whole steem-engine in detail... reading the white-paper is always a great start, though much has developed since then.
Shameless plug: Some pesky details about the reward system on steem that I posted about a few weeks ago.
No worries man, I'm definitely going to read your writings and try to get more involved. I'm so new that I have to figure out who all the big players are, and it seems like you are definitely worth networking with since you freely provide information and seem to have good intentions :-)
Unfortunately I am definitely not a big player... my stake is rather miniscule still :D
but I am always happy to help a fellow out if I can!
Cheers!