The tape is fine
AFAIK. Most don't use any, just the soapy water test. Tanks of any sort and contents are expensive so this is a nice gift. You could add in O2 later if you wish. Check with the torch spec to see if you can use compressed air. It's a low pressure but gives good results. You should be able to braze and silver braze all day long. And you also may be able to adapt a cutting torch with the compressed air.
I was just reading about all this a week ago but I don't remember all I read. It's out there on the Google. I ended up using a propane/O2 setup with a Meco torch and a No. 1 tip (tiny) for some funky jewelry.
[Edit] I wanted to add that I checked with a regulator repair place I use and they told me any acetylene reg cab be used with propane tanks like the 20 lb BBQ type. The hose, if old, might not be rated for continuous propane use.