Magic the Gathering!

Bloodbraid couldn’t be your Commander because she isn’t Legendary. There are no Legendary Creatures with Cascade.

That said, you’d only cascade for 3 CMC or less. The Commander “Tax” doesn’t affect the CMC of the spell.

Assuming it’s power is 3 or greater:

You get to pick how you want to resolve the effects since you are the controller of said effects. So, to do so, you put Packleader’s effect first, Cream of the Crop second. Cream of the Crop resolves, then you can draw it with Packleader’s effect.

603.3b If multiple abilities have triggered since the last time a player received priority, each player, in APNAP order, puts triggered abilities he or she controls on the stack in any order he or she chooses. (See rule 101.4.) Then the game once again checks for and resolves state-based actions until none are performed, then abilities that triggered during this process go on the stack. This process repeats until no new state-based actions are performed and no abilities trigger. Then the appropriate player gets priority.

Before the vampire can do damage it will die if it blocked or became blocked by the Wooden Stake wielding creature. Poof! Ash.

You control the effects in how they happen, since you control the abilities on those permanents. Stack it up!

603.3b If multiple abilities have triggered since the last time a player received priority, each player, in APNAP order, puts triggered abilities he or she controls on the stack in any order he or she chooses. (See rule 101.4.) Then the game once again checks for and resolves state-based actions until none are performed, then abilities that triggered during this process go on the stack. This process repeats until no new state-based actions are performed and no abilities trigger. Then the appropriate player gets priority.

No. Remember, when a card refers to itself by name, it means that specific permanent and not permanents with that same name (unless stated otherwise).

Not normally no. It OMM NOMS the other creature before anything else happens normally.

It happens as soon as all of the attackers have been declared. So, just before blockers are declared. This makes it so that the person defending has even less to defend with or very few lands to come back with.

Yup! Graft says “move a +1/+1 from this creature to another creature,” and Shroud doesn’t prevent that (it prevents targeting).

Yup. Factory would die because Humility makes it a 1/1. If Bridge from Below is in your GY, then yes you have to exile it because a creature enter your opponent’s GY.

Yes. Yes (but not advisable unless you’re doing Battle of Wits).

Yes. You control it now. =3 Happy stealing.