Hard agree on inclusion of Darts and Cue Sports (suspect would ned to get Pool, billiards and Snooker together to make a presentation - plus it would feel more like a family of sports being included) - Darts is to Archery as table tennis is to tennis (and arguably Snooker is to golf, come to think of it). for darts, men's single, women's singles, men's pairs and women's pairs. I'd hold off on the 'team' event for a cycle or two - GBR and NED would still be far too dominant (fight between IRL, CAN, AUS, BEL and USA for the bronze would be cool though).
It occurred to me that such quintessential indoor sports as snooker and darts might actually be best placed at Winter Games, where a small pre-existing multi purpose hall, and relatively small number of players and officials, could create a relatively profitable event for a host. And it would VERY quickly become the pinnacle of the sport!
On bowls and Bowling - again, it seems perverse that the entire family of bowling sports is absent - 10 pin has more world reach, while lawn bowls has a much longer history of Games involvement, especially Commonwealth, and a very established event system - the latter also is rare in being a sport that one can continue to play as one gets older, and while we talk about the Youth of the world, sports that might encourage older people back into activity must be considered a genuine aim with an aging world population.
On the one's to dump, I'd hesitate at dumping 3x3, because I think small sided versions of the big team ball sports should be encouraged - better to have 24 nations repped in 3x3 than try and add an extra 4 teams to the main version, and having watched 3x3 at Youth Olympics, it does have some of the excitement and buzz of rugby sevens (a HUGE hit in Rio, which actually seems to have sparked interest in Rugby in general in Brazil). Indeed, a bigger 3x3 would justify a smaller pool of teams for the 'big event'.
That said, the team sports - especially basketball and football - are big ticket sellers for hosts, which ha to be factored in to why they keep their place.
To be honest, I can live without Karate - it's great fun to watch, but I find the scoring system impossible - the idea that a punch that connects must have some sort of artistic merit....nah - sort that out, you'd be welcome back - if Judo can have 15 events on its own, Taekwondo and Karate can have 16 events between them - so sort out the scoring and THEN come back.
On that note, I'd ditch Greco-Roman wrestling. Male only, somewhat obscure, and wrestling already has 24 events - chop those 8, and all the 'fighting' styles have a rather nice East v west, grappling v striking 'balance' that feels 'complete'
'Western' grappling = wrestling = 16
'Western' striking = boxing=15
'Eastern grappling = judo = 15
'Eastern' striking = Karate + taekwondo = 16
for full balance, i'd split the Judo team events into men's and women's, and add one women's weight category in Boxing.
Skateboarding...I dunno, I'd rather have it than surfing, personally