I try to say all I know on this issue, please mention my mistakes:
well, generally i know we can use participles are adjective:
1) participle 2 as adjective:
1a) it can make PASSIVE adjective with a transitive verb:
- Er ist ein geschlagener Man. ( is correct) (he is kicked)
1b) it can not be used with intransitive verbs:
- Er ist ein gegangener Man. ( would be wrong) (he is GONE???)
2) participle 1 as adjective:
2a) it can be used as active with a transitive verb:
- Er ist ein schlagender Man. (is correct) (he is kicking something or somebody)
2b) it can be used as active with intransitive verb:
- Er ist ein gehender Man. (is correct, at least grammatically) (he is going)
3) participle 1 with ZU as adjective:
3a) it can be used with transitive verbs as passive:
- Er ist ein zu schlagender Man. (correct) ( he should be kicked, or he is to be kicked)
3b) it can not be used with intransitive verbs
- ER ist ein zu gehender Man. (would be wrong) (he is going to go ...)
4) participle 2 with ZU as adjective:
4a) it does not exist
- Er is ein zu geschlagener Man. (would be wrong) ( he should be kicked, or he is to be kicked)
now my points:
1- it is strange in my eyes that in case number 3a, verb is active and participle 1 but Noun is passive (he is kicked, he does not kick)
2- why can not we make adjective with ZU plus participle 2? it could be more meaningful than participle 1 plus zu !