wallkill river...NJ

[njflyguy]

Any of the members here fish it? I am fairly new to flyfishing..this year I decided to hang up the spinning gear in preparation for a trip to Alaska...I must say that if it continues to challenge and reward me the way it has so far I may never take the spinning rod of the rack again....so anyway the real point is I need help with mending and fly selection and was wondering if anyone here would be willing to lend a hand to a newcomer....I pretty much have the forward cast down, the roll cast ussually works out ok..with an occasional pile-up.. 2 last questions (you'll see I'm new when you read them)

1) why do bead head nymphs tangle/hit the end of my rod..dries and streamer/buggers don't give the same problem?
2) why does my leader stay partially coiled when hitting the water..the line rolls out really nice but the leader is partially coiled?

Thank you all in advance for any insight....