Yes that news story is worrying but what on earth were they thinking feeding him what they did at three months old?
I never worried about the salt content in fresh fruit or veg as it would only be trace amounts and you certainly can't quantify it! I just manually calculated what she had in what we cooked or bought. It certainly opened my eyes to how much salt there is in some foods. She loved crumpets, it was only after she bolted her first (and last) one down I checked the packet and discovered there was 1.1g of salt PER crumpet, I was horrified!
Broccoli is a fab first finger food, and pretty much gag free as they gum at the florets (best not overcooked or it just falls apart) so don't really take off chunks. Cucumber and tomato wedges are good, especially freezing cold if they're teething. Cauliflower is also good as well!
Did you 'feed' him baked beans or let him play?
BLW is all about letting them pick it up and eat it. Or you hand them foods that are a little slippery! If you're worried about choking keep him sat in your lap while he feeds then you can solve any issues if they arise. DD only ever 'choked' on cooked carrots, and she dealt with it herself. All other issues were gagging, not choking! But they do make it sound dramatic!