Looking at spending 10-12 days in February. I am looking at the cities below.
Lisbon Evora -Coimbra - Porto/Douro Valley

1. Is this the best order to visit them?
2. Do I need more than one day in Coimbra? (and is an overnight necessary).
3. Do I need to spend a night in Douro Valley? I was looking at a day trip with boat ride/wine tasting/restaurant experience from Porto.
4. From what I am reading it looks like Evora and surrounding areas are similar to the Tuscan region with small towns heavy on great food and wine. How many days should I stay and what are your favorite things to do there?

Thank you - and I welcome any and all suggestions!

It depends on what you want to see and do! I spent two nights in Coimbra, loved every minute. No need to spend a night in the Duoro valley unless you want to. How much time in / around Evora — up to you! A good guide book or two should prove very helpful. Be sure to give Lisbon and Porto enough time for your interests.

Here is our 2022 trip report (millions of photos). This should give you some ideas. Lots of trip reports to choose from on this site.
In order: Lisbon, Sintra, Tomar, Coimbra, Douro Valley and Porto. Have a great time. Portugal is fantastic.

https://travelswithmaitaitom.com/portugal-2022/

We spent two nights in Evora but could have stayed a third night and done day trips in the area, two nights in Porto but could have stayed another night for day trip or boat ride had the weather not been gray and drizzly most of the time we were there in June, just an afternoon in Coimbra where it was extremely hot and three nights in Lisbon which included a day trip to Sintra If I were to do it again, I would have stayed overnight in Sintra.

Soooo many choices! Im thinking about dropping the day trip to Duoro Valley - Ive heard the weather is cold and rainy in Feb and it seems we can visit plenty of wineries in the Evora area.

I enjoyed a visit to the Cartuxa winery just outside Evora -- just an easy taxi ride or longish walk from the center of town, which meant I didn't have to sip and spit. Bonus! The visit included a tour of the winery (not the vineyards), an olive oil tasting, and a personally tailored wine tasting. I booked in advance, another couple joined me just as my tour was starting. Unlike most winery visits I've experienced, Cartuxa let us stay and continue drinking as long as we liked. Nice!

I also enjoyed a port tasting at the Taylor house in Porto (or rather, in Vila Nova de Gaia, just across the river). I'm sure you realize you have many options for port or port & wine tastings in that area.