As to the curved rubber moldings, the channel gets stretched when you pull the molding. I take a pair of channel lock pliers and GENTLY compress the molding channel one plier width at a time until there is about 1/6 - 1/8 inch gap in the channel. Then the molding will stay in place. I also use a wooden mallet to help seat the moldings.

Welcome to the forum and thanks for your detailed input !