I have Powerstretch tights and exp. wt. longs, and mine are about the same in weight and warmth. But either would be too warm for me when on the move. For hiking or XC skiing, I'd be in light baselayer (I have sued light merino wool and various polypro/polyester versions , all with equal success) and ashell pant. My current shells are EPIC fabrica, previous were goretex, both do the job. If your ski pants are just shells (you said 2 layer, but I'm not sure if you meant a 2 layer fabric or that they have 2 layers of fabric) and have ventilation options (sounds like they do with the side vents), they could work. But if they have 2 layers of fabric, even without insulation, then probably too warm unless you are a cool customer, or unless you go without the baselayer.
If you do go with the light baselayer and shells, then bring the exp. wt longs for camp.
On top, it sounds like you'll have plenty. If I'm moving in 30 degree temps, I'll fry in anything more than a light baselayer and a light shell or 100 weight fleece (shell if it's windy, fleece if it's not) - and if the sun is out and there's no wind, probably just the light baselayer. In camp you might want it all - though "ski jacket" can mean a lot of different things, so I'm not clear on what yours is like.
You don't mention handwear - I'm big on layers for the hands - right now I like Powerstretch liners, some old home-knit mittens, and mitten shells. worn in whatever combination suits the conditions. The liner gloves get the most use for me.