1.If you are in employment with the current H1 at the time of switching (or another legal status and the gap of H1<2 month), chance of a denial is slim, unless something is wrong with your new company.
2. Tricky question. The answer is no before you receive the receipt. May be OK after receive the receipt but better not to do it.
3) Not necessarily, as long as the delay is in the reasonble range (usually within a pay period). Sometimes CIS issues RFE for extra pay stubs, you better keep all of them.
4)H1 transfer is quite safe after receiving a receipt assuming you are in status at the time of switching. However, if you don't want to jump to the new employment right away, you can play safe not telling your current employer until an approval is received.
Good Luck
2. Tricky question. The answer is no before you receive the receipt. May be OK after receive the receipt but better not to do it.
3) Not necessarily, as long as the delay is in the reasonble range (usually within a pay period). Sometimes CIS issues RFE for extra pay stubs, you better keep all of them.
4)H1 transfer is quite safe after receiving a receipt assuming you are in status at the time of switching. However, if you don't want to jump to the new employment right away, you can play safe not telling your current employer until an approval is received.
Good Luck