Are lower hours pilots less safe?
It must all depend. But the whole aviation industry values experience. It is seen as a major input into pilots having the 'developed' values which safe transport needs.
If you are barely going to leave the circuit and always operate in a club environment then a low hours pilot is 'adequately' safe. Somewhat better than when he was soloing under tuition but how much?
I have the same argument with collegaues at work - they all claim to be golfers - they are nearly universally crap - they have high handicaps and getting the little ball into the little hole is difficult for them. Why? because they do not practice very much and do not have much experience to sustain their judgement.
Noe a lot of flying related skills are somewhat cerebal, so I'm more than prepared to admit that thinking about these things will help. But in pure dealing with issues, making decisions and aircraft handling, pilots who do not fly regularly cannot have the same skill levels.