Critique of my 1 week in Croatia.

Where are you staying on Day 4 Krka Park?

Overall, I think it's an OK plan. You have limited time, and those are some of my favorite places on the coast. In Split, there's a good Archeological Museum, and Split was an important Roman town for many years. If you can get on a "Palace basement" tour, I'd do that - you get to see the plumbing, and the infrastructure of this huge building.

Having just been to Croatia, here’s what I’d suggest:
Stay in Split for two nights in Diocletian’s Palace. Then pick up your rental car in town and early on day three drive one hour to Krka National Park. Continue to Plitvice National Park and check-in at one of the three Hotels ( Plitvice, Bellevue or Jezero Hotels) inside the Park. That way you can buy a “one day ticket” and be admitted to Plitvice both during the afternoon of your arrival day and the morning of the following day. These admission tickets are only available to guests of the three hotels. This is the best way to avoid the crowds of tour groups.
After viewing Plitvice, return to Split (2.5 hrs) and return the rental car. You can take the Krilo catamaran (75 minutes) or ferry to Hvar. In season, There are boats leaving at 2pm, 4pm and 5pm among others. Overnight in Hvar for two nights ( Yes- Hvar is worth two days!) Continue on the Krilo catamaran (3.hours) to Dubrovnik where you can stay the remaining two nights.

At a steady pace, Split and island and Dubrovnik is a sensible schedule for a week. Taking in the parks is doable, but makes a blur of a trip IMO. Therefore I would do either the parks or an island.

There is far more to the island of Hvar than Hvar town. If you are travelling in June, July or August, I would take the ferry and stay in Stari Grad or Jelsa and take a bus trip to Hvar town. I wouldn’t stay there in peak season as it’s noisy and full of young party goers.

So you are suggesting that I should just the buy tickets in one of those three hotels instead in the plitvice lakes website? I'm going there in June. I like what you are suggesting because I can still explore the plitvice lakes the next morning without a lot of people.

Yes- the three hotels will sell you the ticket after you check in. I think Bellevue Hotel is the least expensive. Because the hotels are a government operation as is Plitvice National Park, they can exclusively offer the ticket for admission over one afternoon and one morning. If you’ve ever viewed a YouTube video of Plitvice Lakes, you’ll see the films show the walkways are often thronged with visitors. So many book tours of the park from Zagreb and Split
that the Park gets really crowded from about 10:30 am to 3 pm. Especially June through August. You can visit outside of these hours and avoid the crowds.
Have a great Trip!