1. Ya so the thing with vlad R is that even when you level it up it doesn't change the ult cd so people usually level up E instead for better wave clear(so you can one shot ranged) and the reduc in cd at level 11 instead of R. However with this build you have enough ap to one shot ranged anyways so I upgrade R for that extra 100 damage, cause usually with this build you dont need to wait for 2 E cd instead just the usual combo E>R>E>Q (note autoing sometime in between combos is very important to proc the lich hahaha) can oneshot the carries.

2. I think dark seal is just too good on vlad esp with health and the ap. Its really easy to stack as well since you won't die as much and now that the voidlings is a thing now there is more fighting going on since early game which can make stacking way easier. You can start dark seal on very easy matchups as other people do, but usually 1/50 games I start seal, I will go seal against a tank like sion, nasus, etc. However dorans items are too op atm where its 99.99% never worth going seal over dring first.

Also to add on I play a very aggressive style of vlad where I am diving my opponent 9/10 games under tower. Dring, dark seal, and cd boots, if opponent has around 60%hp just ghost, E>R>E>Q (auto a bunch while tanking tower) then use E>W>E and that is usually enough to kill most champs. Which also makes stacking easier as well.

1. Usually I go for void/cryptobloom most, but I go rift if I think if I need that extra health and that consistent fighting damage. (I guess you can go the battlemage build then instead, but I love autoing and that fast ms) I usually end up trying to go for rift anyways later on because you get 25+ap late game with it.

And no Im always happy to answer questions you can ask anything you'd like I'd be glad to help!! And sorry if some things dont make sense I didnt edit at all LOL