RO water does come slowly, if for instance your RO membrane rated for 65GPD (gallons per day), then you should be getting around 2-3 gallons per hour (actual production of RO water also depends on water temperature and water pressure). ... so, time it, if it is too slow, then check your water line pressure and compare it to what's membrane's operating pressure is.
Refractometer: this
one might work just fine. Actually many models very similar, so shop around

, what's important is that the unit has Automatic temperature compensation funtionality.
Test kits: I haven't used Aquarium Pharmaceuticals kits so I can't comment on it. Most agree on accuracy and ease of use of Salifert tests. (I use one too. Does this sound like a comercial?

)
As far as waterflow goes, you'd have to experiment on that one. Every tank is different, so there is no one true method of getting water flow setup. Important thing is not having areas in your tank where water is not moving. Stagnant water pockets is usually where detrius ends up accumulating and rotting there. Another imortant point is to avoid laminar flow, rather have it turbulent. THis is achieved by pointing powerheads so their streams intersect; also putting them on wavemaker unit; installing rotating water flow deflectors, etc... trial and error is the only way to go.
Microbubbles: are not usually harmfull, they are rather visually annoying. If this is a new skimmer, then it is normal for some bubbles to escape.
Sand: if you are going for DSB then you need more. Otherwise do whatever is pleasing to your eye. You could always add more to bump up depth an inch or two later.