The healing tide / stream breakpoint isnt worth going to. Theres a bug atm which means you need more haste depending on your latency at the time or something like that and haste being probably our worst stat atm its not worth reforging into to reach this extra tick.
Another breakpoint that people go for if they take the em talent which is my prefered talent, is 2000 and something so you get another tick on healing rain wen you have em up and also the 3039 breakpoint which gives you the extra tick on earthliving weapon since you lose the 5% passive haste from as and doesnt require any reforging into to achieve.
I believe in answer to your second question its all physical damage. I havent tested it so cant be sure what it actually procs off of but i found this with a quick google which might help
http://shamannebula.wordpress.com/ta...-water-shield/
If you are looking for a way to get mana return on all fights, try the totemic recall glyph, just by returning your healing stream totem before the last tick you can return like 300k mana in a fight which is pretty nice mana back, and you can also return your fire / earth ele for more free mana