1

Are you sure you need all those places in the Yucatan? That doesn't sound much fun, bouncing from one place to another for 2 nights each. If I were you, I'd cut one place out so you can spend an extra two nights somewhere else.

For example, if you cut Cozumel, you could spend three nights in Playa and 3 nights in Tulum.

Anyways, as for the last seven days I would definitely pick Mexico City for 7 days! There is more than enough to keep you occupied that long! For example, a week in Mexico City could look like this:

Day 1 - Go to the center, see Bellas Artes, Templo Mayor, and all the other stuff there.
Day 2 - Go down to Coyoacan and San Angel, see Frida Kahlo Museum, Trotsky, etc, wander around...
Day 3 - Have a relaxing morning walking around Condesa, then go down to Xochimilco canals for the afternoon
Day 4 - Teotihuacan pyramids
Day 5 - Parque Chapultepec and all its great museums
Day 6 - Take a day trip somewhere close, like the park at Desierto de los Leones if you want some nature, or Tepotzlan for a charming small town
Day 7 - Go back to the center, enjoy it one more time and go shopping at the Ciudadela.

2

Skip Cancún and add the days to Playa. Unless you want to spend the night in Cozumel or go snorkeling, stay in Playa and take the ferry to Cozumel. Campeche can be done in one day. Seriously, there is not two days of things to do in Campeche. Take the above advise and visit Mexico City.

3

If you have extra days just save it for some place you really like.

4

Thanks to all of you,

Tell me one or two places on the coast between Oaxaca and Morelia ( I have 4 days left) . Acapulco will be out of the list, I'm not interested in.

The place should be reachable by public transportation from Oaxaca and it should be well comunicated with Morelia

5

If you fly from, say Puerto Escondido, or Huatulco, OAX, you can probably do this.
Because of the mountain chains that thread Mexico and the road system, it would be difficult to do this by bus.

I suggest that you look on the websites of some of the Mexican budget airlines, such as Interjet. (Note: I have never used this airline. I am just suggesting you have a look.)

It would be possible to take a bus from Oaxaca to Pto. Escondido, spend a couple of days, take another bus to Huatulco (not very far) and get on a flight from from Huatulco to Mexico, DF. From Mexico, DF you would need to go cross town and get a bus to Morelia.

Only you can decide if it's worth the time and added expense.

If, on the other hand, you wished to visit the Michoacán coast, you could bus out of Morelia to Zihuautanejo, approx 5+ hours.

6

Seven days would be the perfect amount of time to visit the Lake Patzcuaro, Morelia area of Michoacan. If you are interested in "old Mexico", the culture of the Purepecha indians, and one of the best artisan areas of Mexico, Michoacan may be for you. Remember, Michoacan is Magical. Feliz viaje, David