Can we give Gangplank some variety?

Granted, this is coming from a former Support Gangplank player. Admittedly, new Gangplank doesn't really fit that mold anymore, but there are a couple other molds that are being left out as well, and I don't see why...

1. Powder Kegs will activate Sheen and Trinity Force, but it doesn't activate Lich Bane nor Runeglaive, as they are magical damage. It appears that all physical on-hit effects land, in fact, except for Life Steal, unless you get Ravenous Hydra (splash still lifesteals, it would seem?). Can we make Powder Keg actually viable with other on-hits, such as the magical ones? I don't know why you would make Trinity so strong on him, and yet leave Lich Bane flat while keeping his other AP ratios.

2. Silver Serpents. They are basically a way to make GP even more pigeonholed into the "Singed role". Kill minions or be useless, and be as annoying as possible about it. On top of it, Parrrley was basically GP's staple before tossing Silver Serpents into the mix, and they make his Q even more vital, which was unnecessary. While GP is a feast-or-famine type champion in the first place, I don't understand why we'd play even stronger into that niche when his barrels were supposed to be a way out of that, I thought. He was an ultimate and a pistol. Now he's just got more things to shoot, but at least it makes for a strong teamfight effect.

I guess the real question here is, why is Gangplank being given such a higher feast-or-famine quality in his Silver Serpents when he also gets a much stronger teamfighting element planted in his kit to ensure he's plenty feasted regardless? I feel that old GP at least had a better chance of never reaching feast-mode thanks to his binary kit. Can't we just have him farm up his items and leave his kit needing no farming? Why must farming be double-dipped as such?