Mark, the pros seem to rely on Photoshop and Lightroom. I am no pro, I use Paint.Net and Darktable and get by.
For stitching panoramas I use a free program called Autostitch.
I can't recommend a good tripod head, I'm inbetween good tripods. I got rid of my heavyweight aluminum classic, and now have a mistaken cheapie purchase that's wobbly with a metal gimbal. I setup a gimbal with a macro rail to try to get panoramas adjusting for that special turning point to avoid distortion. All too heavy and unstable for the wobbly thing.
Most people nowadays seem to prefer the ball heads as being best due to convenience. I like things that smoothly turn instead, but it all gets very awkward and shin bruising rushing out to get a shot with a big tripod setup. So I mostly don't use a tripod at all and just try to hand guesstimate the turning point for quick panoramas. If they don't work out it's fine, my regular photos are fine enough. And while I have a nice macro lens, I never quite got into focus stacking for macro. Though I did try astro stacking for awhile, the light pollution is just too much here for me to get anywhere with it, I really wanted to get into astro but just have to focus elsewhere -- man proposes God disposes. :)
I mainly just do cloud and sky photography and birds, which occassional flowering plants season permitting.