Understand this. A domain registrar or a hosting company provides services need to keep your website up and running. A Bank or a PSP providers the services to allow you credit card payment acceptance. Your hosting provider will not have any problems if you use a high risk merchant account or a low risk account. They may have problems if you violate there acceptable user policy.
Also keep this in mind that High Risk Merchant Accounts are Legal. They just need to stay in the limits of the card scheme and govt regulations guideline. Not every high risk business gets a merchant account. Some that have limited risk exposure get these accounts. Hope this helps.