With a Dubai Tourism Visa, what else do I need to enter the country?

Because it is expensive for airlines to return passengers who don't have the correct paperwork for UAE back to where the passenger came from the documentation checks are mostly done by airline staff before passengers are allowed to board. The requirements, as expressed by Emirates are, for Egyptian citizens who wish to visit UAE:

Destination - United Arab Emirates (AE)

Passport
Passport required.
Document Validity:
Passports and other documents accepted for entry must be valid for a minimum of 6
months from the arrival date.

Passports and/or passport replacing documents issued to visitors NOT entering via Abu
Dhabi (AUH) for a stay not exceeding 3 months, must be valid for a minimum of 3 months
from the arrival date. 

Admission and Transit Restrictions:
Admission refused to passengers with a hand-written passport at Dubai (DXB).
Additional Information:
Passengers with dual nationality must present the same passport at immigration upon
entry and departure.

Visa
Visa required.
Visa Issuance:
E-visas can be obtained before departure at www.ednrd.ae . Passengers must have a
printed e-visa confirmation and airlines can check the validity of the
e-visa on the same site by clicking on "Query GDRFA-D APP".
Passengers with a normal passport and a confirmation that a visa has been approved
before departure can obtain a visa on arrival for a maximum stay of 96 hours, 30 days
or 90 days.
Passengers must have a passport valid for a minimum of 6 months from the arrival date.
The visa approved before departure must be deposited by the sponsor at the Immigration 
Authorities.

Deportation on the same flight will follow if sponsor (or representative) is not
present at the time of passenger's arrival at the airport.  

.

Additional Information:
All visitors must:
- hold documents for their next destination;
- have sponsor in the UAE to cover their stay.
Valid visas in expired passports are accepted provided accompanied by new passport.
Warning:
Visitors not holding return/onward tickets could be refused entry.

A more authoritative version is TIMATIC where (courtesy of KLM) the nature of "return/onward tickets" is clarified:

Unless stated otherwise, return/onward ticket is defined as:

a. International airline ticket (i.e. any types of airline tickets, reservation confirmation, booking code etc.); or

b. Evidence of departing from the country by other means of transportation (e.g. confirmation of joining a cruise, train, bus or ferry tickets, proof of departing by private boat or plane, etc).

In connection with visas on arrival there is a note Deportation on the same flight will follow if sponsor (or representative) is not present at the time of passenger's arrival at the airport. This is much more forceful wording than Visitors not holding return/onward tickets could be refused entry so it seems possible, though not advisable, to be allowed to enter without a return ticket.

Neither KLM's nor Emirates' version of TIMATIC makes any mention of $1,500 or hotel reservations. However I presume you have arranged somewhere to stay so at least the accommodation should not be difficult to prove anyway.

If you do genuinely intend to depart UAE after a reasonable time and within the limit set by your visa, the chances seem good that you will not have any problems regarding funds and accommodation. You may not have any problems with a return ticket either but I suggest best to "play safe" and buy a return ticket, based on you best guess for when you will want to return as that cost and a change fee, if any, may be better value than a single + the risk you face of being turned away at the border.

When I have attempted entry to UAE it was exceedingly easy - the queue was only four or five people, as far as I can now recall no questions at all, and the stamp was free. However this may be because of my passport, which is not Egyptian, so it may not be quite so easy for you and others.

Also, your agent should be able to provide you a confirmed reservation just before you depart for Dubai (so it is still valid when you arrive in UAE) and then cancel it before any payment is due. That is, air tickets can usually be 'held' by agents for at least 24 hours and sometimes as much as 72 hours.