On Roland G-70 you can use hi-hats and percussion from Power set always and only snare I found is 102: StandrdSnar1 in combination with 8: Room Kick 1,9: Room Kick 2 and 11: Power Kick2 and from Kick&Snare2 set 38: Mix Kick.
For Rock songs with higher tempo you can use Picked Bass 1,2,3 for other songs use Fingered 1,2 or Fretless 1,2.
In mastering section turn off compressor and hold EQ with: HI-2000Hz,+8dB gain
MID-1000Hz,0.5mid Q,0dB gain
LO-200Hz,+8dB gain
Just try to listen and keep smileing.