I'm the same. I stand around until the last minute. We're all getting there at the same time, and I'd rather be standing because soon I have to sit for hours. My bag fits nicely under the seat in front of me.
That's a lot further than just stretching in the aisle..
I'm on the taller side and I apologize for any inconvenience, but I really do need to stretch. Those coast to coast flights will leave me paralyzed for days otherwise.
Depends. The bag can be under the seat in front, pulled up next to your own seat, or even in your lap. If it's under the seat it can be squished up, down, or sideways. If it's too big or overstuffed for that, then you can take one or two things out, or you can check a larger bag to keep the in-cabin one small. Not saying you should have to, but those are all viable alternatives to fighting for overhead space. I'm 6'2" with long legs for my height and I'm not young either, so I do know the struggle, but I used to travel quite a bit on six- and even ten-hour flights and I never felt like putting stuff overhead was an absolute necessity.
If you have a garment bag, I suppose that's a consideration, but I remember there always being "lay on top" free space in the overheads, even if full of bags.
Besides you can’t put stuff under seat in the exit row.