Although ViaMichelin estimates the Madrid-Granada trip at just under 4-1/2 hours, that doesn't include any time for stopping, getting lost, looking for parking, eating lunch or walking from your parking place to the Alhambra. A prudent person would allow considrably longer. I would drive straight to Granada and hope to have time to find something to eat before beginning my Alhsmbra visit. I'd expect to spend between half a day (if you don't try to see everything) and close to an entire day at the Alhambra. The Alhambra is more than the Nasrid Palaces, and Granada is more than the Alhambra.
Toledo is a full-day destination; I recommend at least two nights there. It would make no sense for you to stop there. By the time you dealt with your car and got to the historic center, it would be time to leave. And you'd be putting your Alhambra visit at risk.
How many nights are you spending in Seville? I'm guessing not many since you have allowed so little time in Granada. I'd consider 2 full days the minimum for Seville. If you have less than that, I wouldn't recommend a detour on the way. Seville is one of the very top destinations in Spain. Places you might stop off (unless you are thinking about Cordoba) just are not in the same league. They'd be fine and recommended for visitors with more time.
Spaniards are heavy consumers of ham and other pork products. Ham is often used for seasoning vegetable dishes. You'll want to read the menu carefully and check with your server. Some folks may consider seafood to be vegetarian.
Revueltos are scrambled eggs. You can sometimes find that disdlh without ham, especially at lunchtime. A tortilla is a potato omelet, served as a thick wedge. That is usually vegetarian. You can sometimes find a goat-cheese salad that doesn't include ham.