1. Not heard the rule of not opening 1nt with a useless doubleton in a major but Im sure a variation of it exists - you'll have to ask leo.

 

2. Some people will open 5/5 in the blacks because it is easier to introduce spades at a higher level than introduce clubs

 

For example 1c-1h-pass-2h-2s would instead be... 1s-2h-pass-3h-?

or similar for 1c-1h-pass-3h(preemptive)-3s 

 

This method isn't followed by everyone.