You could use the ball or something else to lift her out of the cage and put her in the bath or a run, then sit in that with her. It would let her get used to you on more neutral ground and might help. Plus then she could wander over when she wanted rather than you going into her space with your hand.
Our roborovski's were rescue hamsters and we're pretty sure at least one of them (Whizz) had been neglected as he didn't even get the idea of burrowing into his woodshavings at first (he gets bedding too), and used to hide whenever we entered the room. The other (Skip) was a bit better but he's never been happy about hands either. To get them out we either coax them into their balls (but Whizz is even scared of going into things when our hands are near them), or get them out in their houses (blocking all exits). We're still in the process of convincing them to let us near the cages without hiding though, so the taming process is being very slow with these two as we don't want to upset them by trying to get them used to hands before they're even confident with us near the cage. We are making progress though
We've also got our russian boys who aren't fully tame yet, so to get them out and reduce the risk of nips (they haven't quite learnt that people don't want to be tasted yet), I've started putting a small plant pot firmly on the end of a toilet roll tube, putting that near the hamsters, then when one goes in (they can't resist it - no idea why) I turn it up and keep my hand to block the end if needed. It works quite well for moving them and they seem to love it.
If your syrian can fit in a tube then a kitchen roll tube and plant pot could work, or I've heard of people using pringles tubes with hamsters and maybe one of those could be used to get her out.
I've not got many ideas on the chewing - Try checking she chews her mineral wheel, that she does use the play wheel, and that she's always got enough food and that her water bottle is working. If she's not chewing the mineral wheel try a different chew toy - We've gone through everything we can think of with our syrian now.
Also it might just be that she enjoys it - Our syrian used to chew to tell us things but now seems to chew because she enjoys it. We don't want to move her into a tank (she'd never get half as much space as she has now) so we're just trying to minimise the risk of injury instead. At least chewing the bars helps her teeth - She won't chew any chew toy more than about twice lol. Her record for using one was a week - she woke us daily pulling it around. Then stopped and went back to her bars.
For potty training try putting dirty litter in the toilet, and cleaning and disinfecting where she goes now. If you do it reguarly enough she might catch on. Or she'll do what our Scamp does and teach you to give up because she thinks she's smarter than you lol
We've had to reach the agreement that she doesn't use her food store as a toilet if she wants to keep it, and are leaving it there. Scamp likes digging in her toilet (more than in her burrowing area) so we're leaving it with litter for digging now lol
Haven't even tried potty training any of our boys - The robo's hardly make much mess at all, and the russians usually all go in one place, so we're letting them do that instead of trying to potty train four of them at once.