as an ex landlord
i can see both sides of this
if i rented out a house now i would insist on 3 months worth of rent as a bond as it now held in a special account i dont see that this is much of a risk for the tenant unless they wreck the place or fail to pay the rent
then ask for at least 1 month in advance this gives you a bit of leeway for payments you need to make if they are a little late and the bond is there to pay if they walk away with out payment and also as a way to give you time if you have to evict them
picking your own tenants helps to prevent problems IF you can say no to ones you dont want
if your one of those who cant say no then get a company that others use and recommend
i dont see the rent thing as a big deal the bit that's a real night mare is the ever changing regulations for gas and the vents for it
you end up with a house with force ten gales going through it and freezing tenants lol