Most of these I've either got the answer from the definition or part of the cryptic clue but I'm struggling to fully understand some of the clues so any pointers appreciated
1) Closely connected room east of renovated marina - ARM IN ARM (get the anagram of marina, unsure where the extra letters come from)
2) Punish students in passage - GATE
3) Artist in London area touching old woman? I'm tickled! - RAINBOW TROUT (Understand where rainbow comes from, not sure about trout or the actual definition)
4) Principle that is barely followed - NUDISM
5) Jam makers live north of church in market town - WISBECH (church -= EC? Not sure about the rest)
6) I roundly criticise religion - ISLAM