1) The only way Crit will alter your self heals is if you were to crit on an Inner Beast or had Bloodbath up or if you were using Second Wind.

2) Determination only affects your outgoing healing, tooltip is rather misleading. Again, this is different if you're referring to self heal via above mentioned skills, but it's strictly from an attack power increase.

3) I could be wrong but I believe you want to be in the 390-410 range depending on latency and rotation timing so that you can fit 9 hits into your Zerk timer.