So I may not be representative of your use case, but I got the steel cap boots for work. I have had bunions before which are caused by pressing in on the side of the big toe, forcing the joint at the side of the ball of the foot to get messed up. When I switched it was a little painful as the toe straightened over time, but it was already sore using other barefoot shoes (Joto soft shoes), so I don't think it was the shoes making the pain.
As for weight, for steel caps absolutely not. The rubber on the bottom is less dense and heavy than other boots so they move more freely and weight less. They are also quite soft for all the top parts so it really is up to you how you tie them and how that applies pressure to your foot. Make them tight and it will feel tight, rerun the laces and you can change where it is tight. I tried using elasticated lace replacements for a while on the lower two pairs of holes and it was good, I ended up using the laces to make it more stable but for normal day comfort I would recommend using elastic lace replacements, much less pressure and no tying of laces.