Don't expect much more from it.
I have several 570's ranging from 26,5 to 28,5Mhs.
I haven't seen more then 28.5 in any 570 to date, so yours is totaly normal performance wise.
really? even my old 470 refs are doing better then the numbers you state.
rx570 can go up to 31. Normally however it hashes around 29.5-30.5
I've got a rig of rx570 4gb MSI gaming with Elpida doing mere 29.4. And the only slower 570 I've got is ASUS Expedition hashing at 28.8
Of course it's possible if you are willing to deal with memory errors in HWinfo.
GPUs can have hundreds of errors and seem to work fine but you have a steady higher stale shares percentage and the ocasional rejected share so i cannot accept 30mh as a 570s normal number.
