How many full days should we allocate to Taian?

Oh, in general, 2 to 3 days are enough for you to visit major attractions in this city. Six days and five nights are too much. So you are suggested to adjust your travel plan. :-)

OK, thank you. Would you please suggest some more places to visit for 2-3 days?
We fly to Nanjing on 24.03 and depart from Harbin by air on 12.04. Please advise.

As of now we have no-penalty cancellable bookings at: Huangshan - 4 nights, 24-28.03, Qufu - 3 nights 28-31.03, Taian - 5 nights.

We also have irrevocable penalty bookings at: Nanjing - 5 nights 20-24.03, Shenyang - 05-08.04 and Harbin 08-12.04.2016.

I also think that 5 nights for Tai An is too much an probably 3 nights for Qufu could be too much as well.

We have purchased railway tickets for 24.01 Nanjing-Huangshan only sa far and are about to buy more railway tickets. We used to visit Hauangshan in the past, visited both historical villages but had no succcess on the mountain itself due to rain and fog. We did visited the mountain and did not see anything and had to go back to hotel after 2 hours on the top. No we booked Crowne Plaza in Huangshan, maybe we will choose a cheaper place in Tunxi?

Please advise if we sould shorten our stays at Huangshan and Qufo (For Taian is clear, ty)and should we visit another places instead. What other places?

Maybe it would better to set a base in Jinan for 4 nights 01-05.04 and to visit both Qufu anf Tai an mountain from there?
Is it a good idea?

What is the distances between Qufu, Taian and Jinan? Are there organized join-in tours offered in Jinan hotels?

I have changed my reservations: booked Huangshan for 3 nights, 24-27.03 and Jinan for 6 nights, 27.03-02.04. I need to be in Shenyang on April 05. Please advise where to spend 3 nights: from April 02 to April 05 before Shenyamg? I have been in Beijing many times, I so not want to go there again.

Here are two ways for your reference:
1. Jinan - Tianjin/Qinhuangdao/Shanhaiguan - Shenyang
2. Huangshan- Shanghai/Hangzhou - Jinan - Shenyang

All the mentioned cities are connected by high speed train and you can conveniently travel by them. For detailed schedule, you can search on your own on this website. By the way, to visit Mt. Taishan, you'd better stay one night there. It's on your way to Jinan.

I like your plan. Maybe we do not need to stay in Jinan at all?

So it might be like that: Huangshan (27.03 >) - Taian (29.03)> Qufu (30.03)>Tanjing >(02.04) >(Qinhuangdao/Shanhaiguan) (05.04) > Shenyang?

or should we avoid Qufu?

I recommend you have a stop in Qufu, maybe arrive there in the morning from Taian and leave in the afternoon. If you feel time is tight, you can spare one day more from Shanhaiguan/ Qinhuangdao.

What should we choose Tianjin or Qinhuangdao/Shanhaiguan in your opinion?

I prefer Tianjin. Qinhuangdao has beautiful beach, wihch will be nice to visit in summer.