.- Getting under contract and then reducing the price because of findings is common, but major reductions are likely to tick off the seller unless you have strong justification.

Fairly common here in Cleveland.

Software is a common question on BiggerPockets.

Should I offer to pay them for their consultation, or are these types of questions common as part of the PM vetting process and is a "courtesy service"?

You'll typically find that travel nurses want a 13 week term as that is the most common length of their contracts.

A common rule of thumb is around $30 to $60 per square foot for light to moderate renovations.

And one more question I've worked with 3 REA thus far but so far none of them communicate timely (it usually take 2-3 days to get a response even when I'm letting them know I want to offer on a property) is this common?

People thankfully aren't stupid and have common sense.

Should I offer to pay them for their consultation, or are these types of questions common as part of the PM vetting process and is a "courtesy service"?

Don't be dumb, use common sense for when to call. 7pm on a Friday is dumb, so is 6am on a Tuesday.