Do I need to worry about the seller's other creditors coming after me once I've bought the assets?

It depends heavily on how the purchase happened. Buying specific assets through a court-approved sale with a vesting order is specifically meant to cut off other creditors' claims from following those assets into your hands. Buying assets directly and privately from a struggling owner, without that court process, leaves more room for an unpaid creditor, or a later-appointed trustee or receiver, to argue that the sale should be unwound, or that certain claims, particularly properly registered secured claims, still attach to what you bought.

Before closing on any asset purchase from a business showing signs of financial trouble, have the seller's assets searched under Ontario's personal property security regime for existing registered security interests, and seriously weigh whether the transaction warrants a formal, court-supervised process given how much more certainty it provides against exactly this kind of risk. The more financially distressed the seller appears, and the larger the purchase, the more that extra certainty tends to be worth the added time and cost of pursuing it properly.