A Talon vs an AP champion looks pretty good on paper. Let's break it down.
Abilities
W Rake: Deals AOE physical damage to a wide area in front of him and slows enemies. The popular AP mids have good creep clearing abilities that could push a traditional ranged AD back to the tower, which then allows the AP champ to gank side lanes. Rake checks this. Although Talon is melee, Rake allows him to safely clear the creep wave when needed. The slow is also nice for ganking and chasing.
E Cutthroat: Instantly appears behind a unit and silences it for 1 second and amplifies subsequent damage dealt to it. This is the key for applying pressures on AP champs. A silenced AP champ feels like a sitting duck and an inexperienced player will try to run, giving Talon a free auto-attack. Cutthroat also resets the auto-attack timer, so you can actually hit twice. Although the silence can be blocked by spell shields, the ability is instantaneous, which makes it very difficult to react against it.
R Shadow Assault: Becomes invisible for 2.5 seconds + 40% movement speed buff (Ghost is only 35% with the mastery); his blades deal physical damage in an area around him. Great ult for a mid laner to have. It makes him extremely difficult to gank, gives him a great chasing mechanic and is a great ganking ability. Plus that 2.07 bonus AD ratio if you Cutthroat them first - ouch.
Stats
Magic Resist: Talon has scaling magic resist. Nice. Most AP mids don't have this extra defense (usually melee champions have scaling MR).
Health Regen: Talon has ~150% the HP regen of AP mids. It'll take much more to harass him out of lane and an AP champ would rather be using that mana to farm.
Movement Speed: Few AP mids (I think only Katarina) have such high base movement speed. This make Talon great at dodging skill shots and ganking side lanes.
Health: He starts off with about an auto-attack's more health than most AP mids. It's a small but comforting advantage in the early levels.
Pick
Talon is rarely picked in ranked games. There's either a more nuanced explanation for his weakness in other parts of the game, or he's just underappreciated. On paper, he looks very strong with a Maw of Malmortius.
I had always assumed that it did, but to make sure, I just tested two cases in a custom game. I did these tests on The Proving Grounds for convenience; the passive gold gain bonus on the map shouldn't affect the results.
In addition, I used Greater Quintessences of Avarice and full points in the Greed mastery for a total of +5 gold per 10 seconds.
I proceeded to purchase a Philosopher's Stone when the in-game clock read 1:00. From here, I did one of two things. In the first case, I cast Whimsy on myself whenever I was alive and ran directly to the Outer Turret. When the in-game clock hit 5:00, I had 1923 gold.
In the second case, after buying the Philosopher's Stone, I sat in my base until 5:00. At that point, I had 1917 gold.
The minor differences can be attributed to the inaccuracy of the client-side game clock.
In short, yes, gold per 10 items still tick while you're dead.
Best Answer
So the awesome GraceNote helped me do some research.
Kog'Maw's passive suicide form is not effected by Ghost or Shurelya's Reverie. However, its speed does ramp up until it explodes into the acidic goo.
Shaco and his hallucinations (and by extension Leblanc's decoy and Yorick's Ghost I believe) do gain the bonus from Shurelya's Reverie.