It looks like your Itinerary is coming together well, The ring of Kerry can be done as a scenic drive but the area does have some excellent spots worth stopping for, personally, I cannot do the ring without at least a stop to admire Ballycarbery Castle or spending some time in Killarney National Park. Ireland.com put a trip idea together that covers some of the best spots to check out. Ring of Kerry
There is a link in there for the Skellig ring
too, which is also a fascinating detour if you are into your history.
Beara is more of scenic drive in the traditional sense but as you mentioned, you would want to make the trip to Garnish Island if you're doing that drive as the pair really go hand in hand. here is a wee article on Beara and Garnish Island
If you are travelling between Glenarrif and Cobh, the best thing to do is take a tour of the Haven Coast
. That link will take you to a 2-day tour, but if you don't have that amount of time. I would at least try to squeeze in Timoleague Abbey and the Old Head of Kinsale
As for your plans for a Medieval/Viking dinner, I am a meat-eater myself, but Bunratty does offer a vegetarian option. You might also want to look at Knappogue Castle. I have not done it myself, however, some of my friends have and tell me it is on a whole other level. They also were able to cater for one of my vegan friends too.
Just as a side point, The area you are visiting is also close to my second favourite spot on the entire island, but then I am a history geek. Craggaunowen
Is just north of Limerick, up by Ennis. There are some excellent reconstructions in there including a ring fort, crannog and a Keep. They usually have people actually living the life on site as well, a proper living history experience and well worth the few extra miles.
Anyway, there is some food for thought.
If you want more suggestions or have any questions about what I have posted, ask away.
I have spent a lot of time kicking about that area.