1. Is it considered bad form to prompt the slow group in front of you to let you play through? No, if they are holding you up continually, then ask. I've done it in the past, and you can usually tell by their response whether there was any chance they would have let you through unpromted before hell froze over.
2. Should a solo player give way to a group even though the group in front is holding him/her up? Never. Solo players have just as much standing on the course now as any grouping, priority is with the quickest group
3. Does a four ball not have to give way to a three ball no matter what? Double negative, but I take it you mean does a four ball have more standing than any other grouping? In which case, no they don't, see #2.
