are there any mods that make it so a degree is needed for certain careers (like Doctor etc)
I loved that you needed to go to university for certain careers in Sims 2 (even if the careers they chose were strange ones)
And it adds more incentive to actually attend university in the game.

There are ways to do that by using NRaas StoryProgression and a caste for each career or set of careers that you want to require a major. The way I usually see players set this up though is not to deny entry into the more demanding careers, but rather to disallow progression beyond a certain job level -- you can empty bedpans if you never went to med school, but you can't do neurosurgery. At least, not while anyone is looking.

The problem I have with this setup myself is that I play somewhat overpopulated worlds and I'm not prepared to send much of the workforce, sims whom I never control actively, through Uni so although realistic that would very much limit many of their career paths. I would probably go around handing out some degrees using DebugEnabler or the honorary ones by way of LTR points if I were to try this, either that or insist on having a Homeworld University that the inactive residents can attend on their own.

Wow, I never knew you could do it with nraas mods, I have story progression for many of the options, but am not really that interested in the majority of my towns population (just friends and family) I have never used the caste stuff before, so will have a look.

Only want to do it for the family I play as (i don't rotate, always just play one family)

So you want your actively played household to be unable to enter or advance through certain careers without a degree but don't mind if their co-workers and bosses, the inactives whom you would never play, sail right through with no credentials?

That's fine if that's what you want of course, but I would think a much simpler solution would be to hands-on guide your sims into the careers you think they would be better qualified for rather than relying on a mod to block them. No good?

Yeah, basically. I like to immerse myself in sims. I want to have to go through the process rather than artificially limit myself.
as I said I loved it in the Sims 2 as I couldn't just "cheat" and pick any career I wanted after the university pack came out.
I liked that I had to work to get some of them.