Mexico - 4 days itinerary - Yucatan Mexico - please advice

We are planing our holidays in Mexico and before "sun bathing" we're planing to spend 4 days visiting the most interesting places in Yucatan.
proposal of our itinerary looks like follows, but maybe you have got any other ideas or suggestions or criticism if something is missing or something is not worth to see having only 4 days ?
please - ..... any comments highly welcomed :)

1 day: arrival to Cancun airport at 6.30 pm and then evening transfer by bus to Chichen Itza or Valladolid (first night)
2 day: visit of Chichen Itza and surroundings till late afternoon (second night)
3 day: Valladolid - sightseeing, walking around city, relax, (third night)
4 day: morning transfer to Uxmal - visit to important places (4th night)
5 day: transfer to Playa del Carmen for 7 days of fun, relax and sun :) but also top have some "local" daily trips to Tulum, Coba ect.

Of course as you can see I put here only some famous places and it is rather an initial idea what to do , but now I need your comments - what to add ? what to cancel ? is it worth to visit Merida ? when ? how to build the best itinerary ? Is it needed to spend whole day in Valladolid or rather is better to go to Merida ?

all comments are appreciated :)

please ...give us your advice :)

best regards
Adam

Sounds ok.

However, I would highly recommend considering a rental car to get around as you will save yourself a lot of time and add experiences to your journey.

Valladolid is nice, but not spectacular. Not sure you need more than a half day to stroll around and spend the night in the zocalo with dinner.
Would be sure to visit a cenote or two. There are 2 near Valladolid on the highway to Piste and Chichen Itza. If you are a little more adventorous, I would recommend a short vist about 10 miles west of Piste to the village of Yodkzonot to visit the recently redone cenote. When I lived there, it was not a tourist location, but now the local women spruced it up in the name of eco-tourism.

I would highly consider visiting Izamal for lunch and stopping along the way to the guyabera factories to get a custom made shirt (1/3 the price i the local villages rather than merida or cancun).

Either way, you will love it. And you'll wish you spent more time exploring the interior rather than 7 days in Playa. Be sure to at least take day trips to Xel-ha/Tulum, etc.

Sounds ok.

However, I would highly recommend considering a rental car to get around as you will save yourself a lot of time and add experiences to your journey.

Valladolid is nice, but not spectacular. Not sure you need more than a half day to stroll around and spend the night in the zocalo with dinner.

And, as if that weren't enough, there aren't, at least to my knowledge, any decent hotels in Valladolid. I stayed in a so-called 4-star with no lift (at least they did have someone to move your stuff up/down), patchy aircon and a dead wi-fi signal. Oh, and the breakfast was HORRIBLE.

Bearable for one night, but I'd rather just drive on to Merida (which is well worth visiting) and stay somewhere nice (while still inexpensive).