Disagree with Accuracy. You should not put ANY points into Accuracy AT ALL. Yes, this means most of the Tionese/Columi/Rakata gear you get from the vendors is awful.
You are correct that no one should PUT points into Accuracy. That being said, every Vanguard is going to get accuracy as one of their stats from end-game gear. Never put any more than that into Accuracy, and if you are lucky enough to find a comparable modification piece to replace one with accuracy, definitely use it.
Harpoon is almost never an opener, and it's actually not very good at building threat. I only use it to reposition enemies for AOEs, and as an interrupt in rare situations.
Like you, I use it to reposition enemies for the purpose of AoE, or as an interrupt. But I will occasionally use it as on opener, in conjuction with Storm; Leap to one enemy group, and pull in a straggler.
Sticky bomb is actually a good opener. It won't put you "into combat" until the projectile actually hits the mob, so your GCD will actually be partially over. If I'm in a situation where I would open with Storm, I will almost always do Sticky -> Storm instead. Don't use your Explosive Surges immediately after your Storm. You have ~12s to use them, so make sure you've spent some ammo first, or they're wasted. A typical Storm opening should be something like
(Sticky Bomb) -> Storm -> Ion Pulse -> Energy Blast -> Ion Pulse -> Explosive Surge (1) -> Ion Pulse -> Explosive Surge (2) -> Stockstrike -> High Impact Bolt
Good advice, I tried this, and I now use it as my opener in almost every scenario. Works great!