Here's something that I can't quite believe I've only just thought of:
What's stopping Lightning users from opening a channel where they (the user) are the owner of both of the multi-sig addresses that constitute the channel?
Answer: nothing.
And that's pretty powerful really, and makes a nonsense of the whole "centralising hubs" or the "subscription payments only" criticisms. Anyone can open a channel and use that as their on-ramp to the Lightning network, without having to involve a 3rd party, or open separate channels with everyone they do business with.
Any drawbacks to this that anyone can think of?
Dude, this is why it is called Lighning
Network. Because you don't need to open a channel with everyone, or just one big hub. It is a transitive property. If you have a channel in common, that is all that is needed. This is the big innovation of it. You can just open a channel with one of your friends and they will have it with someone else and so on. Even if you do open a channel with a hub, you will still have a channel within the circle of your friends and work and so on. They can all make one network with many connection to it. It will be more decentralized then Internet itself.
It will be huge. Is soft-fork needed to activate LN ? After that bitcoin could compete with visa/mastercard
Soft-fork is not needed to activate LN. Segwit soft-fork already happened, but even that wasn't needed, to my knowledge, it was just useful as it was useful for many other second layer technologies, as it fixed the transaction malleability bug.
Right now lighting network theoretically can be delopoyed since the of segwit. We should propabbly wait till after the whole 2x drama before we continue though.
On the hubs though, I also read that you would be able to access someone through someone else's channel. That makes it pretty freaking special. If we are able to perfect it and make it quite user-friendly we've got a banger.