I don't know about Portugal, but in the UK one of the big reasons to start a company is to get limited liability. If someone successfully sues your company, that's bad - but if you don't have a company then they'll sue you and take all your possessions, like your house - much much worse. Bitcoin does absolutely nothing to avoid that scenario. (IANAL etc).
Using bitcoin will only have the effect of restricting the OP's potential number of customers, with no effect whatsoever on the OP's liability if the laws of the country are violated.