KIX to Wakayama, Mt Koya, Kii-Katsuura

I have many questions, hopefully it's not too confusing to put them into 1 post!

We are a family of 2 adults and 2 older teenage sons and are arriving at Kansai airport mid November and planning to go to Wakayama for 1 night, possibly just to sleep or we might visit the doll temple before setting off.

I am considering the idea of hiring a car in Wakayama and then driving to Mt Koya, staying 1 night in a temple, driving to Kii-Katsuura and staying 2 nights in Hotel Urashima to enjoy their onsens, and have a day trip to the Nachi falls, and then make our way to Osaka. Perhaps drive back to Wakayama/Osaka along the costal route.

The questions on my mind are:

1. Would it make sense to drive this route?

2. I can't see make information about driving to Mt Koya, any advice?

3. If we stay at Mt Koya, any suggestions about what temples to try to stay at?

4. There seem to be 2 inland routes from Mt Koya to Kii-Katsuura (which we'd like to try, because we will drive back a different way). Any thoughts about which is more interesting?

5. When arriving, I am thinking of taking the train to Wakayama so not to have to negotiate roads and my first attempt at driving in Japan at night when tired. Or is it easy to get from the airport to Wakayama by car? I am Australian so driving on the left is what we do, so the car will be what I'm used to and am a confident driver.

6. Should I drive from Kii-Katsuura and drop the car off in Wakayama both to avoid a different drop off fee and driving in Osaka, or is it easy to drive in Osaka?

I am quite flexible on the first 2 days (I have already booked hotel Urashima), so I'm very open to other suggestions!

Thanks in advance for your thoughts.

Don't bother trying to drive in Osaka. It is very busy. Just return the car to Wakayama.

Ifve made some posts on a similar itinerary early on in the year.
My thoughts would be:
- Wakayama is nice but not amazing. Ifd stay in the hotel that overlooks the castle and pay the extra for breakfast as the view from the breakfast room looking over the castle is lovely. Therefs a very good seafood restaurant within 10 mins walk, right opposite the (?Kani Dourakou?) crab restaurant with the animatronic giant crab over the door
- Marina City is good for the tuna cutting demo and for great seafood lunch
- driving or public transport from Kix to Wakayama is fairly easy
- driving to Koyasan is easy and scenic. I would choose the route from Koyasan to Katsuura that takes you via Shirahama and stop briefly for a dip in saki no Yu the seaside onsen, which is awesome
- Ifd only stay one night at hotel Urashima. The two outdoor/seaside onsens are very good but the hotel is ordinary. For a second night I would go inland to see some of the Kumano shrines and stay at Kawayu onsen or the other lovely little onsen place close by with the hot stream running through it and whose name escapes me at the moment
- therefs a good Visit Wakayama website, and also a good Kumano Kodo one
- there are some good NHK World programmes covering the area which might be available on the web on demand. You can do a lacquerware workshop at Kainan and also visit the soy sauce brewery at Yuasa if that sort of stuff interests you.