As a former landlord, this is my understanding (and as I applied it).
All people listed on he lease are responsible for paying the rent. If the rent is not paid, the courts expect the landlord to start one action to recover the debt, not two. That means if you can’t find your cotenant, you wear the whole owing rent, even if you paid your part to the landlord.
The bond is required to be in the name of all tenants mentioned on the lease. But again if there is damage, the landlord gets his money back from one bond. If the bond does not cover the damage, the landlord can recover from any person named on the lease money’s owing.
When entering into a cotenanty, you need to have absolute trust that your cotenanty is trustworthy, as you will be responsible for all debts incurred if they can’t be found.
As landlord, if I was renting to a non married couple, I insisted on both names being on the lease because I had twice the chance of recovering my money should the partnership collapse and one partner, or both skipped out. This actually happened once. I took the remaining tenant to court, and they ruled in my favour and made the one former tenant who I could locate pay the judgement.
It may be better to continue your lease in your name and set up a sub tenancy agreement with your friend. Make sure it’s in writing and signed by both.
That way, whilst you are still responsible for all debts, at least you can’t be kicked out if the friend does not pay the rent but you will have to take them to court to recover your money.