Your house looks like it could go a bit contemporary so maybe the railing could be black metal and eiter glass panels or just the same metal for spindles and beef up the columns

Just because they may not be primary weight bearing does not mean they aren't helping out, especially the corner post. Home style is so mixed these days it is often very difficult to determine. Your home has some features that look Georgian, but those houses were mostly brick and lacked covered porches. When they did have a porch the columns were round. Nonetheless, I see no reason square posts would not work, just make sure their size is comparable to what you have.

sketchup is easy to use for 3D drawings. You would just measure the porch and reproduce it in sketchup. You can use a layer for each option.

I‘m in Cali too. Not sure, but it looks like the LA metro area. The thing that immediately stood out for me is the landscape mix of rocks and brick. I would have chosen one or the other. I could see a pale yellow on the stucco (I think the current color is too close to the roof color; reminds me of the popular colors of the 90s). I could also see removing the wrought iron decorative post (not sure if that is orginal based in the design) and put in a railing along that side, with a design tilting toward the 1950s. I am not the biggest fan of security doors, but understand why some really like the functionality of it. If it were my house, I would remove the security door and put in a stained wooden door. Love the original mail slot. I have a 1950s house too that is in Los Angeles proper that has the white wood siding too (vertical vs horizontal slats), but the stucco parts are a dark green with a dark brown painted front door. We also have wrought iron, but in the house. It acts as a wall near our staircase. I doubt ours is original too as the design does not fit the year the house was built (1958-59).