Basically it's not a different coin but it's the same coin but the different purpose only. steatlh coin can be converted into another form of veil coin like RingCT coin. I thought that it has very well explained by veil whitepaper. You can try to send a little amount of stealth coin to the Bv address and it will be automatically converted.

Yes, they need to release the lite version of their blockchain because many people cannot keep on downloading such a huge large file for the wallet sync. It is generating very good volume in the market and that is a very good indication where we can hold the coin long term due to because we are seeing development activities from the team.