Rivera is a much better defensive catcher than Pier and probably slightly better than Bethancourt. He's also played most of his games in SD and Sea so will he's not a good hitter, he may not be embarrassing bad either.
Jennings is another good defensive player. He's about a 3-3.5 win player. I don't think Gomes/KJ put up a 3 win season.
Kiermaier will be better than our center fielders without hitting a lick as he's a borderline gold glove center fielder.
Smyyly has a career ERA of 3.26 with an FIP of 3.45 and xFIP of 3.65 in the AL playing in front of an awful Tigers defense. Miller has a career 3.33 ERA with a 4.03 FIP and 4.08 xFIP in the National League.
BP projects the Rays to score 694 runs and give up 638. It projects the Braves to score 577 and give up 654. Offensively, they might be close to equal, though I would give the Rays the edge because they don't have as many black holes in the lineup as we do. But, they are far better defensively. And their pitching staff is deep.
The teams you list outside of SF and TB have a good chance of being worse than us.
Again, we're just spitballing and guessing, but when things start to go south, they tend to snowball and go that way in a hurry - that's why I included Tampa and San Francisco on my list. Both teams have already been bitten by the injury bug before leaving camp and are counting on several unknowns without long track records (Kiermaier, Rivera, and Franklin for TB, and Belt and Panik for SF), not to mention Mad-Bum pitched mad innings last season, Huddy and Peavy are a year older, they don't appear to have any ready replacements if someone goes down, and (probably most importantly) it's an odd-numbered year. That's the only reason I say they could wind up being worse - both teams have about as many question marks as we do (although several of theirs have higher potential upside IF they work out).