The drawback to using a foam roller is the air bubbles. You can try switching to a mohair roller short nap, but if you are not using a self levelling paint, then you will see some roller stipple in the finish. You are probably having trouble with brushmarks because any paint you can buy at Home Depot or Lowes is probably not high enough quality to actually lie down and flatten out, even with extender. Personally, I don't mind the slight stipple in the finish...it's better than brushmarks and it's certainly better than air bubbles.

It's easy to get a perfect finish on painted furniture when you spray it, but it's true it is hard to get it perfect without spraying. I would stain them if they were mine, just because maple looks great stained and stained furniture is easier to take care of, but this probably depends on what else is around in the room as well. If you stain, you want to stain, let dry, apply one coat sanding sealer and then at least one coat of poly. There are water based finishes on the market now but I don't like any of them. Lacquer can only be sprayed so. You want to lightly sand after the sealer coat because applying any first coat of finish on stained wood will raise the grain and make the surface very rough. The easiest way to apply stain is with a staining pad. Using gel stain or not won't make a difference to your wrist.

Thank you both. I did insist, so there will be two coats. But - another question has arisen. The can of BM Advance paint says to wait 16 hours after the first coat to sand and add a second coat. What would happen if we waited only two hours, when it feels dry? Would that really cause problems?

If it was my office I do White, It will keep the room looking bigger & brighter Due to the assymetry, All white or a very hint of light grey I would choose a color pallete for the whole room before choosing. Choose colors that inspire your best office work. You can also do all white built-in then decorate with pops of color decor.