Bad Habit - If you've bought a warbird but are asking a question like that I'd wonder if you have enough experience to be flying a warbird ????????????
That said I've always been advised to strart with lower rates as long as they're enough to control and fly the plane properly and as you get used to that and are comfortable flying the plane like that then slowly increase them, if you go too far for your 1st flight and it's a more advanced / responsive plane than your previous plane chances are you'll need a bin liner with you. Start low and increase if neccassary is a lot better than destroyed plane and wish it hadn't been so sensitive !!!!!