[ Would you ever harm your crush? If so, what circumstances would cause you to do so? ]

Yes, ranging from firm loving swats with a riding crop, to breaking their legs for relentless, disgusting disloyal, behavior. Thats something I really don't want to end up doing.
I once caught the person I loved in the past lying to me about so many things, for a long time, so I had their crotch branded with my name on it. (maybe that should've been in one of those "most yandere thing you ever did" topics) I admit, it made me very sad that I did something like that to them, but I feel guilty of enjoying it too.
So double yes, I'd do it with love all the way to pure heartbroken yandere levels.

[ Would you ever take your crush's life? If so, what circumstances would cause you to do so? ]

Yes, if they keep pushing me to do it. Most likely, I'd do it out of extreme stress if I couldn't keep them. But if they want to leave me without dieing, they need to do it quickly without playing games with me.

[ Is blackmailing your crush out of the question? Why? ]
No, some people just don't listen to reason, and the best way to keep them safe is to give them more incentive to behave. Sometimes, it's the only way to keep somebody from doing something stupid without hog tieing them down on a table.

[ How far would you take your advances on your crush before beginning a true (read:consensual) relationship with them? ]
The moment I sense they have a weakness for me. They'll be all mine for sure~

[ If your crush was already in a relationship, what would you do? ]
I could sit back and wait to strike, then join in, take them away with my charms and then give them some time to say their goodbyes, and then make them break it off. Or else.
If all else fails, there is the weapon of seductive, sweet words, remaining calm, and causing their relationship to eventually fall apart. If I'm certain this crush is the only one for me, the person they're with is going to leave through any means necessary by my will.

[ What would you do to keep your crush in check? ]

The usual, stalking, asking questions, and talking with them, and reminding them that I will always figure out if their lying, and even prove that they will never be able to get away with anything. Making it known and deeply established that I'm a lot smarter then they'd be giving me credit for if they thought I won't notice even the slightest thing.

[ Would you give your lover permission to harm you? Why? ]

Of course, I'm a bit of a masochist myself. I'm definately not perfect, and may hurt my lover unintentionally, in which case I would give them my permission specifically only if it made them feel better.

[ If your lover were to threaten you, how would you calm them down? ]

I'd hold a finger to their lips, tell them to calm down and be quiet, stroke their hair, and kiss them passionately and deeply on their lips to assure they're still my entire universe, and if it takes more then that; Nothing is more reassuring then leading them into passionate sex till they can't even remember being sad or angry. I'd make sure them being upset at me again would be very unlikely. Whatever issue they had with me previously probably wouldn't happen again, I'd learn from it and make sure they're far too satisfied with me to give me problems.

[ Would you be willing to cut off contact from the rest of society (yes, even the internet), if it meant living peacefully with your lover? ]

I've done so in the past. I see no reason not too.

[ Given the choice, would you prefer a violent or a tame yandere? Why? ]

Both are wonderful, but tame is more reasonable. If she is going to do something violent and impulsive, I rather she be tame enough to consult me about it first, so we can do it together as a team. I'd really hate it if she got hurt or arrested or made a mistake, all alone. It'd make me very sad.

[ Does a Stockholm Syndrome relationship count as consensual? ]

I'm quite sure it is even though most people wouldn't see it that way. >.>
In the end, they are giving their consent willfully.

[ What circumstances would make you consider breaking up with a yandere? ]

There isn't one. I wouldn't even let death part me from them. The whole idea of breaking up with a dedicated, loving, loyal, yandere seems pointlessly stupid to me. Somebody like that holds lots of value.
Or rather IS invaluable. Pricelessly so.