1# ~ Is It or It's not cheating using Faendal to level up your archery to level 50 by doing the trick where you spend the money and then take it back and rinse and repeat?
Depends on how you look at it. At a technical level it's likely an exploit that was overlooked by the devs, from a RP perspective it seems reasonable that a "companion" would teach you archery for free.
Incidentally, I realized, rather belatedly, that you can pickpocket back money you spend on training (if you have decent PP skill)
2# ~ Is it or It's not cheating doing the trick with iron daggers to level up smiting faster, and as well for other such skills, enchanting, alchemy ETC?
Not sure what the "trick" with iron daggers is unless you mean just making a thousand daggers and maxing skill out. It wasn't at the time and you can't even do it anymore, your skill gains are tied to the value of the item so you would need to make an incalculable number of daggers to level up now.
All the skills have a "material" gate that can, to some degree, be mitigated by gold (and copious use of the "wait" command) so I don't see anything wrong with maximising your skill gains (getting sleep in your own bed/switching to the stone that govern's that skill).