Excellent questions. I also would like to know around these questions. The funny doesn't found no one Lightning Node on the 1ml of Greenlight. Where's these Nodes? 


Questions to be answered about Greenlight:
- user do not know or control the routes of a payment
- user do not know upfront the fees charged for a payment
- user do not control the peers of that LN pool. Maybe some of them are "bad actors" trying to analyze and log all payments... that could end up in a surveillance mechanism. I would like to know who are the peers of that greenlight node.
- users cannot trace the opening / closing channel txs. In case of low fees / high fees environment this could create multiple issues and funds lost.

I know that Blockstream do not bother answering support tickets or SN comments. Is just to raise a warning for the users of Greenlight apps (there are quite many now).

From my personal experience testing Greenlight, I would suggest caution! Use it with limited amount of sats.