No.
Just try to be opportunistic and take land from France when possible, i've seen the AI do it.
France and/or the British Islands are your best options if you wish to expand...
Your merchants can't compete because of (1) high Infamy (2) low Stability (3) mercantilism instead of free trade.
You would have been better off waiting until you got the mission to conquer Ireland... it halves the Infamy penalty and rewards you with free cores on all of Ireland.
Don't forget you have to manually select your casus belli when you declare war on someone or else your infamy and stability will take a huge hit otherwise.
I suspect that may have been my mistake. I restarted, made sure the quest was active and conquered Ireland with no difficulties and now my economy is doing well.
Today I witnessed Finland form Scandinavia and Ireland beat England to death. I think I'm going to lie down now...