I'm just coming back too, but...
1. I think the difficulty of the monsters past 71 makes it not worth it to "magic find". If I recall correctly, the drop rate used to be lowered past level 71 as well, but I could be wrong about that.
2. Enhanced Effect is the main stat you want to look for. Also check out this thread and keep items that fit the criteria to sell:
https://forums.d2jsp.org/topic.php?t=60608527&f=273&o=16502a. I haven't bought a vault yet (50fg/30 days), so keeping white can clog your inventory over time. I have transferred a bunch of whites to other characters, but if you find a well in the maze you can't log out to get the whites and then transfer them back because the maze will reset and your well will be gone. So on the note I recommend just keeping a few if you can and hope for a well, but otherwise just focus on keeping the items in the link I posted above.
3. Playing on a phone kind of sucks. I just did a full maze that took three hours on my iPad the other night and accidentally shrined a good item that I'd found earlier in my climb. I probably wouldn't have made the mistake if I were on a computer.
4. Good question, I've been wondering the game. I think it depends on what level you are and what level the map is. If you outlevel the map I don't think you're going to get much experience at all, so probably best to stick with regular catacombs for the most part.
5. I think it's best to try to complete it, but you'll find when you get to be a higher level that you're never going to be playing long enough to complete the whole thing if you're just playing solo (which is what I do).
6. Unsure about this as well, because I never whistle. I can see how whistling might be better if you're playing mobile, but you can't find the evil presences if you stand in one spot, and that's where you can find good items.
This post was edited by Vaeflare on Oct 9 2020 01:40pm