You can only use the write-offs against passive income unless you are a real estate professional or married to one and file jointly...which is why many successful realtors use syndication as a tax shield. 

If we are made aware the minor will come of age relatively soon, I would add a condition to the addendum that "Johnny Jones" will need to sign a new addendum at that time, and become a "Joint and several" responsible party to the Rental Agreement since you always require all adults to be signatories.As a side note, when a household consists of multiple adults, we consider the combined total income to meet the "X times the rent" criteria; NOT that each person must meet that criteria.

and I have met the oldest of creative financing teachers Albert Lowery, and my best mentor was without peer, The wonderful Barney ZickIf you can get some used books by Mr Lowry, check Amazon, you will get ideas on how to be truly creative using money and real estateA lot of Internet boards whether it's BiggerPockets or someplace else don't dive deep enough into being creative and it's your job as a real estate investor to go talk to title companies and attorneys about how to get win-win agreements with sellers of real estate and yourself, The Real Estate Investor, using such as tools as sub two, joint ventures, private lending, equity participation, options, bundle of rights, etc.

Additionally, most of the time the tenants as a group (like roommates) are joint and severally liable, so if one roommate causes 50k in damages all will be sued and all are liable for the 50k balance to the landlord, and they can then go after one another to decide who owes what.What I don't like about the rider is that the lease is automatically terminated.

Are they a team player and commit to the joint goal or process even if their idea was rejected?

If you have less than 10k, but you are well connected with people who have money, then you might be able to pitch a Joint Venture project with a family member or private lender to make it work with almost no money down by sharing the equity and cashflow.50,000 CAD - 100,000 CADWith 50-100k capital, I went to Sudbury Ontario and bought a Triplex for 400k.

How the joint-tenancy was considered (in case one leaves)?

Due to the interlocking joints, you cannot do this (assuming a floating floor).

@Justin Herrington still active in Ontario but working doing joint ventures as qualifying for a mortgage as a non-resident requires more money and more hoops to go through.

Community property states see you essentially as one person because all of your property is owned by both of you jointly.