That sync progress seems reasonable. Best case is around 8 hours and that can change dramatically based on hardware and/or bandwidth. I’d probably just let it run.
As for those options you need to run zcashd --help and you can enable them by adding the line to your zcash.conf or starting with that option i.e. zcashd -dbcache=450 (it’s the same as bitcoind)
-par=<n>
Set the number of script verification threads (-4 to 16, 0 = auto, <0 =
leave that many cores free, default: 0)
-dbcache=<n>
Set database cache size in megabytes (4 to 16384, default: 450)
Edit: replied before I saw this answer here: Zec qt wallet - pls help! - #19 by ChileBob