Look at the PDFs of "Installation Instructions" for both units.
Yes, see PDFs at bottom of closer's web page.
I don't recommend submerging in water :p But it is tough build closer
Yes. I installed it on a very heavy wooden door
Only by removing unit or removing small bolts that hold arm joints together. But no designed Hold Open mechanism.
They have "adjuster valves", so I assume that implies a hydraulic mechanism.
Allows for "parallel arm" installation. See PDF instructions for closers of interest. Access PDFs at bottom of closer's web page.
there's a screw for speed resistance and ond for opening and closing resistance Very simple to do
Look under the heading "Product Overview" on the right you will see a link for "instructions". The instruction page gives you the exact measurements and bolt pattern.