I don't see anything in your signature list that would pose a real threat to a live guppy Cripp. How do these guppies look in the tank they are coming from? Is your tank water similar in chemical composition, pH, TDS, hardness, to the water the fish are coming from? IME guppies are tough as nails fish, but I have been led to believe that is no longer the case by people here and elsewhere. I also do not worry much about putting a guppy with a betta because I would not keep a betta that was a real threat to anything besides another betta. I have seen lots of people who think a betta is a threat to almost any other fish but it just does not match my own experience. I presently have a nice red male in my 120 gallon community tank and a nice blue male in a 45 gallon tank that has pretty much just wild type endlers, him and a few habrosus cories. Both are good citizens in their respective tanks and don't really bother anyone else.