Regarding the 20h match rule instead of 24h: I think this was a good thing. I'll give an example why. I come home from work at, say, 5 to 5:30pm, log on to Elements looking for a league match, and I play one with Player X. So far so good. The next day, I do the same thing. I come home from work at the same time, log on to Elements looking for a game, and Player X is there again as well. However, I just played with Player X less than 24 hours ago, and Player X is not able to wait another half hour to play, so we end up waiting 2 days apart to play instead of 1.
Regarding the bans: I had a lot of fun with this sort of thing some days. Sometimes we had some really wild ideas for bans, or restricted ourselves to certain types of decks, and so on. For instance, there were times we'd agree on maximum of 2 copies of a card, or whatever. One time I remember me and justaburd both agreed to play monolife :p It allows for the option of making things more interesting, but since it is not required, one can always revert to the unrestricted metagame if desired.