1) Bumping of older topics depends on how old we're talking. As a general rule, any thread where the last post was about, say, 6 months old, it could be that perhaps bumping isn't the best idea. However, if you have something you really think will add value to the discussion and keep it running then use your discretion. Check to see if the topic is kind of done with, or perhaps the original poster is no longer active. Push comes to shove, start your own thread and if you think it merits a mention, reference the older one as a reason why you began a new discussion. If someone (other than staff) takes issue with it, we can cross that bridge as and when we come to it. Generally though, people are pretty chill and if you're saying something other than "lol yeh dat Dante tho", it's unlikely anyone will get annoyed at an innocent thread revival.
2) the example you gave is not an issue - double posting only really applies to lots of posts in a thread in quick succession - posting the next day isn't double posting. All members, I believe, can edit their posts to include previously forgotten information or addendums, so there really isn't a reason for anyone to double post. If it's overlooked, staff can merge posts if necessary and first "offences", if you like, tend to go unwarned. If you were someone who kept on posting like a madman then you'd be spoken to, but as far as I can see that will never be an issue for you.
All in all, the rules exist mostly to avoid spammers and trolls - if in doubt, just ask any member of staff or indeed any member who's been here for a while.
EDIT: I double post and spam all the time. One of these days I'll give myself a stern talking-to, but right now I simply don't have the inclination...
BTW stay put of bloody-disgusting website. They posted semi-spoiler in thumb
