Please drive carefully: scientists plan to transport volatile antimatter for first time
(www.theguardian.com)
Why does "theory" carry starker claim absolute truth to you?
Theory, theoretical, these are not claims to absolute truth. Rules maybe, but then id say you're more correct that they'd be rules of a model.
Relativity is a theory. Its in the name. You might not like it, but it is definitely a theory, and referred to as such by all of science. Maybe you call it model of special relativity, but you'd be the exception. However it would not be incorrect to refer to it as a model, either.