I’m getting ready to replace some missing PVC trim boards and wanted to get a few opinions before I start.

There’s a gap at one of the inside corners. Is it okay to leave that gap when I install the new PVC trim board, or should I try to close it up if it matters

In another area, the outer corner is a little rough. Would proper prep and repainting be enough to make that look good, or should I repair the corner before painting?

I also have a section in the centre where the PVC trim is sticking out. If it isn’t just a missing fastener and there’s nothing solid behind it to screw into, would it make sense to add a small wood backing/blocking strip behind the trim so I have something solid to fasten into?

For the new PVC trim, I plan to countersink the screws, sink or pull old nails,  fill the holes with bondo, sand smooth and repaint with a Sherwin-Williams Emerald Exterior, which I read this product doesnt require a primer, hopefully so. 

Install the new piece with a nailer to get it held in place, then sink screws. 

Any feedback would be appreciated; anything different I should do, please share. Also, is there anything else besides bondo that works just as well to get a perfect smooth finish on vinyl? 

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