Short Answers:
1.) do i need express pass at that time of year?
In general, No
2.) we do not want to go out to eat for every meal, how difficult will that be if we don't have club level?
Difficult but not impossible
3.) is a park hopper worth it? (we usually hop at disney, it's not necessary but we like having the flexibility)
Yes
Long Answers:
1.) do i need express pass at that time of year?
It depends on how long you are going to go for and what your kids will ride. If you are only going to the parks one or two days and if your kids will want to ride coasters together over and over, I'd get the express. When mine were that age, they wanted to ride the coasters and thrill rides back to back like 10 times in a row each. Having EP was amazing for that. If you just want to see everything once or twice or are going for a week, there's no need that time of year, especially if you guys are ok using the single rider line.
Crowds are generally low, but as people catch on, it can be hit or miss. I have done Feb trips in the past where absolutely everything was a walk on, and I have gone expecting short waits to find the parks crowded instead.
What is your goal? How is your family with waits? If the concern is fitting everything in, that is more than doable without EP. If the concern is never waiting more than 5 to 10 minutes, you'll need EP.
We are going the entire first week of February and will not have EP. I'm not worried about it at all. We discussed it, and decided we'd rather have money to spend on eating out, souvenirs, and maybe some other activities than EP which we won't really need, especially if we rope drop which we will. We are planning on spending half of each day in the parks and then going back to the room in the afternoon after lunch as we both still have to work.
If you have a full week, you will have more than enough time to see everything more than once. As pointed out above, Universal is much smaller than Disney. Our first trip, we did 3 days at Universal, 1at SW, and 1 at BG. It was perfect. We will probably do some non-Universal activities this February as well, maybe SW if I can catch a good deal. We don't need 6 full days at Universal as much as we love it, not in February. In the summer when it is hot enough to swim, it's a little different as we spend a lot of time resort hopping and enjoying the different pools, but I'm expecting it will be too cold for that.
3.) is a park hopper worth it? (we usually hop at disney, it's not necessary but we like having the flexibility)
As far as hopping parks, I highly recommend it. At Disney, I never do it as it eats up too much time to switch parks, but at Universal, switching parks is super quick and easy. You can be in another park in the same amount of time it would take you to simply walk from one side of MK to the other. At the front of the park, it’s a short 5 minute walk from exit to entrance. At most, it might take you 20 minutes total to get from attraction A in one park to attraction B in the other park by the front gates. If you are at the back of the park, you can take the Hogwarts Express which is an attraction in itself. Because of how quick and easy it is to change parks, we find ourselves switching parks once or twice, sometimes 3 times, in a day.
The same with visiting Citywalk. Visiting Disney Springs takes some time and effort, but Universal’s version, CityWalk, is right there. The entrances to both parks are actually located inside CityWalk, so it is super quick and easy to leave a park and have lunch in CityWalk. In addition, another thing that helps is that security is before you enter CityWalk, so you don’t have to go back through security when entering each park as long as you don’t leave CityWalk.
2.) we do not want to go out to eat for every meal, how difficult will that be if we don't have club level?
I'm not aware of any room at Universal with a full size fridge with freezer. This makes it so much harder to eat in the rooms. Like you, at Disney we do the condos with full kitchens and plan simple meals for the room like frozen pizza or corn dogs. At Universal, there aren't even microwaves in most of the rooms. Although, some hotels do have heating areas with microwaves you can use in the common areas. You will definately have to get creative with meals if you don't plan on eating out.
Crazy idea as I'm a big fan of staying on property, but have you looked at Vista Cay condos? We've gotten some great deals on them before. They are very close to the parks and would give you a full kitchen. The benefits to staying on site are early entry and ease of access with walking paths and boats, but in the winter when you probably won't be hopping back each afternoon to hang by the pool anyway, that might not be a deal breaker, especially if you have an entire week. You won't need to worry with early entry if you have a whole week. Staying offsite in a condo might be a good option in your situation if not eating out is a deal breaker for you.
You could also look at split stays. 1 night gives you 2 days worth of EP, so if you wanted to do part of the time at a preimier resort and then the rest offsite or at a value, that could save you some money. We've done that before during busy times of the year, and it worked out great. You let the kids ride all the coastsers and rides with long waits or ones they want to do over and over the days with EP, then you do everything else on the other days (shows, meals, window shopping, low wait rides, character meets, etc).