Friends, Very first time trying to mine.

I have MSI RX480 4GB card and I am getting 22mhs.

I have this in my .bat file:
setx GPU_FORCE_64BIT_PTR 0
setx GPU_MAX_HEAP_SIZE 100
setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_SINGLE_ALLOC_PERCENT 100
EthDcrMiner64.exe -epool eu1.ethermine.org:4444 -ewal 0x9f9db14f7302e2872fe4662d853d62a2dfec47bf.starzen -epsw x

AND nothing in config.txt file.

I would like to know,
1. which driver is good for this MSI RX480 4GB GPU
2. what should I put in config.txt for better hash performance and temperature of GPU wise and may be other factor
3. Do I need to change my .bat file for better performance.

Thanks in advance