Popa, I’m glad you don’t run the Torah world! (I’m glad I don’t either). There’s no halachic basis for refusing to convert the vast majority of sincere gerim simply because some of them might go off the derech or not be 100% observant to start out. Sure, if the ger says I don’t intend to observe X or Y, or I accept the yoke of 612 of the mitzvos only, he can’t be converted. But there’s no halachic basis for rejecting converts who say they accept everything (and who have a sponsoring rabbi to vouch for their observance). Remember that the basic halacha does not actually require full observance before conversion.
It’s a mitzvah to accept sincere converts. No one but the ger really knows what his or her intentions are. When the ger says the right things to the beit din, they have to convert him. You can’t refuse to fulfill a mitzvah because things might not turn out well. That’s like saying Jews shouldn’t get married because then one day if he won’t give her a get she’ll remarry anyway, with no get or with a forced get, and produce mamzerim.
It appears that some people have the mistaken impression that it’s easy to convert, and that all kinds of inappropriate candidates are accepted. Not true — nowadays, most gerim spend at least a year, often several years, learning and becoming observant. Mistakes may be made, but that doesn’t mean we should make standards 100 times more stringent than the actual halacha requires.