When you open a new credit card, it often will come with 0% APR for a certain amount of months. This user recommends
remembering that new purchases on a balance transfer often do not come with this same benefit.
“If you sign up for a 0% APR on balance transfers for X months, keep in mind that it might not come with 0% APR on new purchases for X months months. So, any additional purchases you make with that new CC will accrue interest and in order to remove the new purchases and avoid paying interest, you'd have to pay off the entire balance.
I'd just focus on getting the best BT CC and if you want to look for other CCs with decent rewards, sign up for them separately.
For example, you wouldn't sign up for a Citi Premier CC with an 80k bonus if you spend $4k in the first 3 months because you wouldn't want to make new purchases on this CC after processing your BT unless you don't mind paying the interest.”