So if they get admitted, we are officially in a hot war with Russia?
States which have ethnic disputes or external territorial disputes, including irredentist claims, or internal jurisdictional disputes must settle those disputes by peaceful means in accordance with OSCE principles. Resolution of such disputes would be a factor in determining whether to invite a state to join the Alliance.
Doubt it. Here's the bit from the NATO site
They aren't going to let Ukraine in just to immediately have to go to war because of Article 5. You have to get all members to agree to let you in.