This is an old thread, but I was just looking at these today and thought I would add my 2 cents for anyone else who might stumble across this in the future. On the patio doors I looked at, the spacer was aluminum/steel/silver colored and was just too noticeable. I can see how you could see through narrower grills (or see odd shadow/light patterns), but I don't think we would do the SDL even if they didn't cost extra.

Q1&Q2: Have had Wolf IR char-broiler and currently have Capital hybrid grill. Both are gas, can't speak to electric grills other than an explicative-laced tirade on my Jenn-Air of long ago. The smoke levels are about the same (impossible to test as can't run both side-by-side). What is more important than the smoke is the total amount of effluent (hot air, steam and grease)--those should be very similar and need to be exhausted. Q1 and Q 2 pretty much noes in my opinion. We had a 600CFM VH oversized over the Wolf and a 1200CFM Modern-aire (similarly sized) over the Capital. The VH did a good job, the Modern-aire clears everything. We found the usual formulae for computing CFMs based on BTUs not so helpful given the susceptibility of the effluent to air cross currents and kitchen layout. The VH was in a fairly tight and contained northern kitchen, the MA is in a house with heat pumps that move a large volume of air and the additional CFMs were necessary. For us bottom line was to go as powerful as we could due to grill, stirfry and panbroiling. If the grill is part of the range or rangetop, the price differential should be minimal other than overall range brand price differentials. Module installs will probably vary by brand. A separate grill would probably be higher cost due to larger hood and and installation costs. Probably not the answer you may have wanted . . .

You brought back a memory of a Farberware indoor grill we received as a gift years ago. As I recall, it did an okay job of cooking whatever we put on it. I can't remember anything about temperature adjustments. However, as you said, cleaning ours was a major production. It's the main reason we got rid of it. Also, at the time we did not have much storage space. I found a photo online of what ours looked like. Hopefully your Rival Grill is less of a contraption than this one was.

In answer to your question...yes, a horizontal bar across your front sliders to that they appear to look like the double hung near your door would be a good look. Even better, why not a vertical grid, too, on each slider, and then one on the double hung, so you have what appears to be a two over two window?