Critique my holding deposit agreement

[Bienes Raices]

[moderators: sorry I posted this by mistake on the Commercial Real Estate forum and then reposted here. Could you please delete the one on the Commercial forum]

So far, I have been having the tenants pay the holding deposit and then only sign the lease the day before move in. However I'm thinking it may be better to have them sign the lease immediately when they provide the holding deposit. My questions are:

1) Should I demand the pet deposit up front with the holding deposit or wait until they move in?

2) If tenant pays holding deposit, signs lease well in advance of move in date, and then never moves in/pays rent, can language be put in the lease that voids the lease in this scenario or would I still need to go through the formalities of eviction/declaring the property abandoned?

Here is the clause I've come up with:

Tenant agrees to pay holding fee of ________ to reserve property until start of lease on __________. At that time holding deposit will convert to security deposit. Tenant will also have to provide additional pet deposit (if applicable) at the beginning of the lease for the lease to take effect. Tenant understands that holding deposit is non-refundable in the event that tenant does not sign lease and take occupancy of the unit.