The match against Real Betis is actually not a difficult thing for Barcelona, especially if the match takes place at Barcelona's cage. Apart from the performance that Barcelona is openly superior to, Real Betis itself is also not a team that is more reckoned with by some people this season
The H2H between Barcelona and Real Betis is clear, Barcelona has a high win rate. What's more this season, their performance is much better prepared compared to the start of last season. And seeing how Xavi is polishing and preparing his team, it looks like Barcelona will win against Real Betis later . Maybe it won't be as easy as against a small club, because however, sometimes Real Betis puts up quite intense resistance.Atletico Madrid haven't made much change in their squad for this season. This is a usual thing for Atletico Madrid so I'm not surprised with that. However they have still made a good progress compared to last season. Because this time Atletico Madrid started the season really strongly. Especially that win by 7-0 was brutal. 
Yes, it seems so. Atletico Madrid haven't changed much. But at least, so far at the start of the season, they have done quite well. It won't be easy. And it might stay like last season, being at number 3 again. Yes, at least, they can participate again in the UCL. Because if they want to take over the position of Barcelona or Real Madrid, this might be difficult.