Well, I guess I am completely misunderstanding how to play, because I thought attack speed helped with basic attacks, and since that is what I am doing 90% of the time with GP items with attack speed would be of benefit.
Although you are basic attacking, most of the time your damage to enemy champions comes from your Q.
I have yet to reach end game in a match with GP, usually matches are over by the time I hit 14-15. I have built the Statikk Shiv once, but it kills my gold production, so it would only be viable as my last purchase.
Keep in mind that Avarice Blade increases your gold production only by about 5% at most in most cases, not too significant of a difference
Also, the tooltip says basic attacks release the energy, so how does it synergyze with my Q (Parrrley, right?)
Parrrley counts as a basic attack for the purposes of items, including this, ravenous hydra, and even Sheen (And therefore triforce's too). It also can critically strike, just like a basic attack (Whereas most spells cannot). Its cooldown however is reduced by cooldown reduction, not by attack speed.
The one time I got it, I never got to use it because we won before I left the shop. How fast do the charges build up?
It only takes about 10 seconds to get from 0 to 100%. In addition, this item's active crits whenever you crit with the attack that triggers it, making it a lot better than it sounds.
You say that the Trinity Force is mainly useful for the passives, but I thought the other stats stacked? Health, mana, movement speed, attack speed, critical strike, and it adds physical and magical damage (Unless tooltip in-game,
For the trinity force, the ability power, attack damage, attack speed, crit chance, health, and mana stack.
However, as both the "Spellblade" passive and "Rage" passive are labeled "Unique", they do not stack, which reduces the effectiveness of the item greatly.
Ability power in low numbers isn't too useful for gangplank, even though his ultimate and his oranges scale off of it, as he still won't be using them too much.
GP's ultimate uses AP not AD for damage. At least that's what it showed on my screen, and I even asked someone about it in a game.)
30 extra ability power will increase his ultimate damage by less than 5 per second, a negligible amount.
80 attack damage and 25% crit chance is comparable to the trinity force on its own. However, the main strength of the Infinity Edge is its Unique Passive, which increases damage dealt by your crits from 200% to 250%. Essentially, this means that if you have 300 attack damage and are level 15, an achievable number, if you had a trinity force AND an infinity edge, a Parrrley would do:
300+ (200% base AD from spellblade) 198 =498 if it does not crit (35% chance of critting)
and
300*2.5 (from crit)+198= 948 damage if it DOES crit.
This is an average of 655.5 damage from your Parrley
However, if you had two trinity forces a parrrley would do:
250 (50 less ad from building trinity force instead of IE) +198=448 if it does not crit (20% chance)
250*2+198=698 if it does crit.
This is 498 average damage from your Parrley.
That's a difference of 157 damage on average per shot, which is HUGE.
There are all the other bonuses, but they nowhere near add up to the benefit of an item with a unique passive, as you can probably see through the math.
This applies to a lot of other items too. Generally, unique passives are what makes each item worth it.
As far as starting out, I chose the Long Sword because it's something that builds into the thing I need, whereas the shield and Dorian's blade do not.
This makes sense. However, Doran's Shield and Doran's Blade are much, much more cost efficient than a longsword. They usually help you stay in lane longer, which can lead to a lot more gold, especially as Gangplank, who either needs to get into melee range to get creeps and take harass, or start to run out of mana. They are also useful throughout the midgame.