ok2pus:
I noticed that they (responses) are just "tricks" or some kind of undocumented solutions to make Studio work. Is that the case here?
Is Studio so buggy that upgrading to nwewer versions seems a waste money?
OK,
WELCOME to the forum. 
Since this is a user forum, and not a Pinnacle-staffed support line, most of what we know is based on the observations and experiences of many users, but we don't have any inside knowledge of the code that makes Studio tick. We also don't have the power to fix anything. So in a way, we know a lot of "tricks" to working around variuos problems. Pinnacle moderates do review posts and chime in from time-to-time, and they have been known to be helpful, but don't expect them to show up since it really is a user forum.
Is upgrading a waste of money? Individual results vary, and it depends on what you do. Many people are very happy with S14. Others are having some serious issues, especially in the Import area. On the other hand, you also get some nifty add-ons at a decent price.
My advice it to wait a while (as you have already done), browse the forums, and see if the reported problems - especially ones that can be confirmed by other people - will impact what you do.
If there is trouble importing a certain type of footage, but you use a different type, then it's not a problem. But if that is the same type your camera produces, and the problem has been confirmed by other people, then you'd probably want to wait for a patch and see if it's fixed then.
I focus on the "confirmed by other people" aspect because Studio is a complex tool, and most people have lots of other software and hardware installed (we tend to be hobbyists with lots of junk installed, though some people have systems dedicated to Studio) and a lot of individuals will report a problem that nobody else can reproduce. It doesn't mean they are not having that problem, but it also means it probably won't affect you if nobody else can reproduce it on their system.
Take both the reports of disaster and glowing success stories with a grain of salt. Then when (if) you do upgrade, simply do so with your eyes open and with an awareness of what you're getting into.
Good luck and have fun.