Thanks for hint!
Disabling FAST-RAM didn't solve problem in 100%, but...
Real Amiga:
solved sound problem
didn't quite solve graphics errors, but it's now acceptable
WinUAE:
same errors as on real Amiga, but here:
bug 1 (flashing dots): I solved by slightly moving screen vertically and hiding this behind an overlay
bug 2 (flying pixel from left to right): disappeared after setting SUBPIXEL DISPLAY EMULATION
Another cool demo added to my project
Thanks again for your help.