Upgrade ship weapons to as high a particle beam as you can. Buy and use ship parts. upgrade your shields.
He stops handing them out for a while, but does restart eventually.
Also if you choose to do a multi NG+ run, any temple powers you do not pick up are available in a later one. What I mean is, if on your first NG+ game you only upgrade 3 powers to lvl 2, the next run will (eventually) let you get ALL powers to lvl 3.
That wording has not changed from the beginning. The conversion on a 'new' GPU from Gold is/was a special promo, and of late it has not been publicized at all.
Someone will have to try it to confirm if it is still live.
For those who might not know (and assuming the conversion would still work): If you have an existing GPU, you must let it lapse for at least 24 hrs before buying Gold and converting to GPU.