All the selection circles in StarCraft are frames in a GRP file, and there's no selection circle that is five times larger than that of the command center. So you'd need to add your own selection circle image there, except I can't remember what the selection circle GRP is called...
The selection circle and unit size parts of Arsenal III are buggy and don't seem to change anything, plus they are labelled wrongly as well. You can use either Arsenal Zero to change how much space a unit takes on the map or use that Unit Resizer program made by Black

, but Arsenal III won't help you there.
The selection circle frame in that GRP file is chosen in sprites.dat. I think Arsenal III can change that, but if you're going to edit sprites.dat, I would recommend getting into the habit of using Arsenal Zero.
If you want flames on the temple, maybe you could just set its health to be below 30% or whatever it is... although you could bring out iscript to do it, but there are two reasons not to do it with iscript. First, it's easier, and second, you'll find the flames in StarCraft have palettes that look wrong, and so it's easier just to let StarCraft deal with that. I think LO? files store the positions of where flames pop up, but I don't know if LOEdit can edit those.
About glowing bits on your temple, if you're thinking about glowing like the Nexus glows when its producing probes, you'd need to do that with an overlay. Blizzard did that with an overlay because that way you can use StarCraft's blue palette which has a special blending mode. You can research this if you want, but again, glows, like flames, use palettes that don't look right using RetroGRP's palettes, and no one's bothered to find us an intuitive palette for those yet.
If you're going to make this part of a map, maybe what you could do is have the actual temple unit have dimensions 1,1,1,1 so it's tiny, but make the building graphic huge. Those dimensions would make the building take up the same amount of space on the map as it would in StarCraft X-tra Editor special mode. Then you could make it so you can walk up ramps and things by placing doodads or your own invisible buildings on the areas of the temple where you can't walk.