You can't since your runes will be deposited if you use the pool.
technically I could add something so you can use UIM mode and drop runes to do this but I don't think it will be worth.
You can just buy a rune pouch voucher from the grand exchange to get the rune pouch
Exp rates go up the higher the runes your craft.
I had around 40k/h at 85 RC with colossal pouch, so 43k seems normal if you are not crafting bloods
It will always hop to a GOTR world, nonetheless if you select hop worlds regardless of what you select if that's your issue
Enjoy!