Imperials Changing Alliances

I know I will get a lot of bashing for this but anyways, here I go

Right to the point, Imperials have no questline which is kinda sad. I think the amount that you pay to recieve an Imperial edition is a little high according to the contents in it (just my opinion). My reason to buy DLCs is to support the developers though. Anyways due to some possible disbalances that my occur, this idea has been put off the table although there was a vast majortiy who were quite positive about changing their alliances. So I think changing alliances may be possible in some conditions. Imperials are known for their treachery anyways right?

Every once in 5 veteran ranks (V5 V10 V15)

By completing the Cadwell's quests. (Cadwell's Gold/Silver)

Imperials are not ethnic to any alliance or area (except Cyrodiil of course). And since they can take part in any alliance that wouldn't cause a disbalance in the manners of RP.

Or we could have a last chance to choose after the Cadwell's Gold.

This option would also boost the sales of Imperial editions. Just sayiiinnn Zenimax