With all tab and slot kits like yours, the key to having it look nice is the trim strips used to hide the tabs and slots. Notice how the tabs on the dormer (or whatever you call the little thing in natural wood color on the roof). Hiding those is the key. Next time you may want to paint the trim strips before you apply them. That way you can paint not just the top but all the sides also. And of course as pointed out, it'll make adding contrasting trim easier, much easier
I even go so far with mine to add a filler (I like Squadron white not green putty) between the lap joints at the corners to make it appear as if the wood trim is 1 piece not 2. You can also go to a hobby store and buy precut wood 90 degree angle pieces and use those instead of the flat strips in the kit.
To get around the different amounts of paint that get absorbed by the wood you can do 2 things. Paint the basic sides before you add the details, that way the glue that leaks out from under the trim won't hamper the wood from accepting color. Of course it'd be best to not let any glue escape from under the trim, that's where kits with the pre-stickied trim is a nice idea but I've had mixed results myself with how well that type of trim sticks. The other thing to help hide uneven paint is to add some basic weathering, but you aren't at that stage you're still building the kit. ;D
Having said all that, looks nice, I'm sure the finished kit will look pretty good.