La Val rouge is crap, don’t bother with that lift at all. Rhodadendrum is great, 10k downhill with loads of variety. The enduros are mainly good but rockyline is a bit rubbish. For the time you are intending to stay there, Tignes is ideal. The campsite less so if you don’t have a car, there may be another up in the village though. The free pass also gets you entry to the pool and health spa if you fancy it.
Last year, some of the runs were closed due to late snow postponed work on the pistes, I still rode for 4/5 days without being bored. Also, queues are way smaller than the pds so you can ride a lot. For a short lowish budget trip, it’s ideal :-)
I reckon a shuttle from geneva would be pretty expensive, maybe better to fly to albertville if possible. Alternatively hire a car in geneva.