A: 1) There is a huge problem with taking the cost out of the damage deposit because the deposit isn't yours in the first place. You must claim against the deposit in accordance with the Act or you can wind up having to pay double the amount back to the tenant.
2) As the landlord you are required to follow section 25 of the Regulations - inventory the possessions left behind, store the goods, keep particulars for 2 years, and inform the tenant(s) as to how the property can be retrieved and/or how it was disposed of. Be careful when disposing of other peoples'property. You can only dispose of property that has a market value of less than $500; the cost of removing, storing and selling the property would be less than its value; and/or the storage of the property would be unsanitary or unsafe.
You are well advised to photograph each item and be prepared to show what is garbage and what isn't - you'd be surprised at what some people find valuable and others want to toss out.
3) The tenant(s) has 2 years from the end of the tenancy to apply for return of the security deposit; 1 year if he leaves no forwarding address. The landlord has 15 days from the end of the tenancy to claim against the deposit but up to one year in a case where the tenant cannot be found and has not left a forwarding address. [Note - if you know how to find the tenant pretending you don't and avoiding making a reasonable effort to locate the tenant doesn't wash.]