Pricing Doubt

for question 1 yes, can be made, by assigning a different document pricing procedure on the quotation document type & SO document type in VOV8.

for question 2 yes, if we design this condition as a manual condition type & do the price adjustment during invoice creation at VF01 ( cos saving the document will lead to account posting & hence may not be possible later).

if you want an automatic value only at invoice level, u can use access sequence that will have billing type as a parameter.

regards

ilango