#knitting advice

Oooooops. Most of the way through grafting this knitted-sideways fingerless mitt, I finally try to try it on and... can't. The edge is WAY too tight from the floats being carried up every other row. It barely stretches at all.

Any advice on a stretchier edge in stripes? All the techniques I can find advertised for garter stitch selvedges or striped selvedges are about the look of the thing (which I don't mind at all), not elasticity.

My knit stitches are ok, but when it comes to purls or cables its real bad. I try to keep my grip relaxed and not pull my stitches too tight, and I often use needles a size or two bigger than what's called for to compensate, but by the time I get a few rows in its always become so tight that it becomes a struggle to get my needles in and my fingers get so sore from forcing the stitches. Sometimes they feel bruised after a knitting session because I was using so much pressure

It doesn't seem to make a difference what kind of needles I'm using either. Metal, bamboo, circulars, dpns, its all the same. I've actually been scared I would snap my bamboo dpns because of how bad it is - I haven't, yet, but I've stopped using them for projects I'm afraid will be too tight

Should I do some exercises that isn't a project so that I'm forced to focus on my technique instead of the project? Should I use even bigger needles? Are there different purl techniques that help with tight tension? I knit continental style, so maybe I should give other styles a try? Are some types of yarn more forgiving? Sometimes it's so bad that it discourages me from knitting when I otherwise want to because it's such a struggle and I don't like being held back by that :(

What does one even DO with a Swift?

The box describes using it to hold what I would call a hank of yarn— the kind that is just a really big loop that maybe got twisted on itself to coil up smaller?

But.

I don't USE those? I have one (1) hank of yarn ever, all my yarn comes in skeins already and they unwind easy enough?

I've been trying to make a blanket, I've casted on about 3 dozen times and started 2x. I haven't gotten too many rows in so far but my tails are still ridiculously long and i think my cast on a bit too tight still?

This is my second attempt and my first attempt trying German twist cast on i think it's called but it still feels a bit tight and the edges, (at least on the one side?) Are kinda like sloping still.

..then i woke up this morning and realised its probably bc i forgot you're supposed to cast on with a bigget size needle than your project🤦‍♀️. But my question is do you think this will be ok? I'm 15 rows in already and I'd like to not have to frog it all AGAIN but am i gonna have to?