Skipping the grind to get to the story would be more inline with the other premium options. Call it a "Story Rush" rather than a skip. Take all the mainline quests from Awakening to The New War and have the new player go through each one in turn. This will provide the core of the story, gameplay, and progression experience they can work from afterwards.
Accelerated progression will be important. Each time they finish a main quest, they get rewards. Unlock a whole planet of the star chart after each quest as though they had cleared it. Give them new weapons, companions, and a careful selection of fully fused basic mods each time as well. Boost their affinity gain within the missions, so they can rank up as they go without having to stop and grind. Maybe also give them one or two new warframes (they ones they didn't pick at the beginning, or something more specialized like Frost) over the course of the whole Rush.
Everything else, like side quests and syndicate grinding, can be done normally. The new player can start on them between main quests or after they've done The New War. I wouldn't bother giving them any forma. It won't be the best possible experience, but for a new player trying to break in without spending two weeks vacation on it, this is probably the best option to get into the swing of things. Probably a better value for playtime than a lot of other non-f2p games that end after you've finished.
