Florida has had a SW license for close to 20 years, and it doesn't seem to hurt the tourist trade one single bit. Also, the federal registration isn't going to be necessary to fish--only to keep any bass or shad that you catch. They can't stop you from fishing for "bluefish" as long as you release any bass that you "accidently" catch
The simple fact of the matter is that in Florida and along the Gulf Coast, not only didn't a license stop people from fishing, but in every instance fishing got better after a license was instituted. The fisheries were managed better. It let the politicians know how many people fish. For many years in Florida, the commercial netters blocked attempts to institute an inshore net ban by backroom deals in Tallahassee. The Florida Sportsman took a look at how mnay licenses were issued, and figured that getting a net ban on the referendum ballot, as an amendment to the state constitution, was feasible. They did, and it passed with 72% of the votes.