I know everyone has their own opinion on things and they differ from others but I don't really see how ppl can say Arrow is a terrible show or they didn't like after only watching a couple of episodes. That universe is almost a complete copy of the Dark Knight trilogy as far as it's environment and feeling. Except this Green Arrow is actually a martial artist and can really fight. It really is a perfect place to introduce certain things in the DC universe. It's by far the best comic book show we've ever had. The first season is really the origin and transition of the character and set in a more realistic and grounded universe. Season 2 takes off like a bullet into the DC universe and really expands the show's reaches and where they're willing to go. I haven't been as impressed with a show's second season as much as this in a long time. Now yes it is a CW show so it doesn't lack drama, especially the first season and parts of the second season (although the second half of the second season has been pretty straight comic booky and action packed) But to each their own I guess, I'm just encouraging those who started to watch it and stopped, to give it another try. It's definitely worth it imo.
As far as the show being connected to the movie universe, I can see the positives and the negatives. Although the only real negative I see is that it sort of restricts what the show can and can't use but I think the DC universe is big enough to work with if that's the case. And the same as for the movies having to follow the events in Arrow, although honestly I don't think there's much the movies would really have to worry about because any other major characters that would appear in films probably wouldn't end up on the show anyways. Connecting the TV and movie universes wouldn't really benefit the movies all that much but the TV shows would get a tremendous boost for sure. Arrow gets a solid 2-3 million viewers which is good for the CW. That would definitely double, maybe triple if they announce their connected. I think a lot rides on this Flash tv show. That will be the tell-tell sign what WB wants to do.
As far as Stephen Amell goes, he has completely grown as an actor and into the role. He could definitely hold his own in a big budget movie, I have absolutely no doubt about that. And it's not like we're going to get a solo Green Arrow movie anytime soon like others have mentioned. I really think he'd be a great addition to a JLA movie but it's definitely not a necessity. And he wouldn't need a huge part in the movie either, just a small part that contributes to the team.
And I definitely do agree that some of the actors and actresses on the show aren't very good but they wouldn't appear in a movie anyways so I don't see how that argument really holds up, Stephen Amell would be the only one from the show to would ever need to appear in a movie. (And yes, he and Cavill have been hanging out a lot lately which has really got ppl wondering)
I know I've illustrated a few reasons for why it wouldn't necessarily be a bad thing if the show was connected but I'm not saying it needs to be. Sure I think would be cool but I wouldn't be all that bummed if they aren't connected.