#2 is the biggest problem I've faced. It's nigh impossible to truly revamp what you have while also having to sell/serve/use/change the existing product. You either have to leadership who is willing to take the hit and stop new features/bugfixes from coming in while you're redoing the product, or you have to pad timelines for new features/bugfixes but that's risky too because you can be seen as someone moving too slow