Honestly, if that were my house, I would leave it as is. It may look more disconnected IRL, but it looks fine to me. What I would focus on is replacing the caulking where needed, adding caulk where needed, fixing any dings or dints and do a really nice paint job. Your nice wainscotting adds a lot of interest in lieu of nice big hefty trim. I would hesitate to tear out and redo it to accomodate taller base. You really don't have room for wider door and window trim in some areas. Once the caulk and paint have cured, I would do a nice strait edge with tape and touch up the wall paint - it appears that the trim paint is running up on the walls.

I don't know if there is a "rule" but a 1/2" baseboard dying into a 3/4" casing, even allowing for a casing edge profile, looks nice.

A picture of the whole room is what I would need to see. Are you planning drapes or what kind of window covering? I don’t think it would look right to paint the trim like the walls in fact I think the baseboards and the trim could be wider.

There are too many decisions when you’re building a home (I assume it’s a new build, but even just a reno has so many decisions). Who is installing your trim? Sometimes you can have someone who is good with suggestions or can put together different profiles for you to consider. In general, you want your home style to coordinate outside and in. That’s why I asked what the outside looks like. From the windows, I am imagining something that’s more transitional - something between traditional and contemporary. It doesn’t look craftsman, but sometimes the simplicity of the craftsman profiles work well in a transitional home. Here is a guide to different moldings. It starts out very traditional, which I don’t imagine your house being. https://kelleher.com/wp-content/uploads/Catalog_Web_DesignGuide.pdf Here is another: https://www.metrie.com/the-finished-space/baseboard-styles For my personal home, I have shaker cabinets and went fairly simple with moulding. 9” baseboard with a simple chamfered top. No crown moulding. Built up window moldings (taller since there is no crown), but still pretty simple. Your cabinetry style can help inform your choices. Are yours flat panel or are those just paint samples?