If all I have for income is alimony income and interest income (totalling less than $75K), and only deduction is property taxes, can I use a simple 1040 to file?

Unfortunately no.

To report alimony income, you must use the new Schedule 1 that is added to the new tax form 1040.

To report interest income greater than $1,000, you must use Schedule B.

To tax property taxes as an itemized deduction, you must use Schedule A.

All of these forms can be prepared in TurboTax Online Deluxe, but not in Free Edition.