I started out as a hand quilter. I never could FMQ well on a sit down machine. My brain is just not wired to "move the paper" (the quilt sandwich) as opposed to moving the "pen" (the sewing machine needle). I did practice, I drew to learn thread paths and I never got better but more importantly I did not enjoy the process at all. I hated making the quilt sandwich with a white hot passion. Manipulating even a small quilt under the machine was nothing like practicing on small manageable sandwichs and even with small pieces my quilting looked awful. All the same things you state, uneven stitches (that was the least of my problems), no smooth flowing lines (aka wonky), squarcles instead of circles, ad nauseum. I was tense the entire time and even short sessions resulted in neck and shoulder pain and I have a machine that is recessed in a table with a large smooth surface. I did ok with straight line walking foot quilting. So I did mostly that and anything fancy I hand quilted.
Then I discovered rack machine quilting with a stitch regulator. My quilting universe had a super nova! No more making the sandwich, no more stiff neck and shoulders, no more dreading the quilting part and gorgeous quilting right out of the gate. Now not everyone takes to it as quickly as I did but it made all the difference for me. Not everyone has the room for a rack set up even though there are setups for a domestic machine or stretch machine that can be mounted on a rack, it isn't all just longarms. But I opted for making the investment of a longarm and I haven't looked back. Here are links to my domestic machine quilting and my first quilt off the longarm and what I am doing now:
https://www.quiltingboard.com/pictures-f5/puss-center-exercise-fmq-t54829.html
https://www.quiltingboard.com/pictures-f5/my-first-quilt-off-longarm-t77776.html
https://www.quiltingboard.com/pictures-f5/4-patch-posy-quilting-t289353.html[SUB][SUP]
I feel if I had not gotten my own LA I would probably be sending my tops out for quilting. There is nothing wrong with quilting by check. Before I got my LA I did send a top out and was extremely pleased with it. You can get a lot of quilts quilted for the price of a LA setup.