Are my boots too big?

maybe they are too loose. or you should wear some bigger socks

You shouldn't really lean BACK so much, but still have a forward lean in your boots while centering your weight back a little

In saying that, you only want a tiny bit of movement in your boots
A good set of footbeds will help to centralise your foot and minimise any movement..when you are moving all over the biit e.g. side to side, significantly in the heel etc then there is an issue with the initial fit.

How old are they? Have the liners seen better days?

Oh and in my opinion thicker socks won't do shit, but thats just me.

They're pretty new. Used them for 6 days, it's the FT Booter

Sounds like their too big. When you are standing straight up in your boots your toes should be touching the front. If you can't get smaller boots right away you can get toe inserts that take up room in the toe box. Also, an after market foot bed on top of your current foot bed will take up space. Try superfeet.

do the hardshell check. take the liner out and put your foot in. if you have more than an inch in the back then theyre to big

your boots have packed out since youve bought them. maybe get some bigger socks or tighten your boots up a little. all boots start to pack out a little bit after ride them for a few days, sometimes up to like a quarter of an inch.