A non-parasitic tail-cunt does not lay eggs (and it cannot get '
fed' either).
Even if you turn your parasitic tail into a non-parasitic one it no longer lays eggs (Even more on that if you use Catnip while your cunt-tail is pregnant with eggs it will just straight remove the pregnancy).
Yes, you get to access most of the Tail-cunt scenes.
Although, some of the sex scenes (Mainly, the ones on Mhen'ga) assume that the tail is parasitic and still say stuff like 'parasitic pussy' in the scenes.
You do lose access to some scenes since they require the tail to be parasitic.
The ones that I know of (that require your tail to be parasitic since that they are mainly about you losing control over the 'hunger' of the tail).
But thankfully, given that it's no longer parasitic you are no longer blocked from either
Kimber's or
Bianca's Sex menu.
Currently, they is only the
Tentacool Pill that can give you a completely non-parasitic cunt-tail. (You need an already existing normal tail to be TF'd into a Cunt-tail)
Like AboutAverage2 said you can turn a parasitic tail into a non-parasitic one with either
Catnip or
Fox/Frostfire.
I'm pretty sure that they is a Zaika TF in the works that's meant to give you Genti-tails (I think even a 'Herm' type tail as well).