I think he's competent despite the fact he's a relic of the "fundies and neocons" era of the GOP, and I think part of why he keeps a low profile is because he's smart enough not to get into unneeded spats over a fairly powerless office.
I do think he'd be able to wipe the floor with Kamala Harris in a debate if he's given a briefing to go after the weak spots of Kamala that are more likely to be brought up in a debate. This is all in the public knowledge, so Pence brushing up on it just before the debate begins isn't cheating.
Ironically enough, I think the DNC and their MSM comrades are more likely to allow a debate between Kamala and Pence than one between Biden and Trump. Biden is in severe decline in terms of his cognitive abilities, while Kamala is not.
Also, I do think the Dems would underestimate Pence in a debate and think they'd be able to win easily against him since he is a Religious Right throwback and they know how to beat that kind of opponent. But Pence seems to be well aware of the myriad issues with Kamala Harris that can more or less sink voter turnout from progressives, leftists, and blacks and as long as he's smart enough to not fall for the inevitable media Kafka traps and start raving on about Biblical morality or the gays, he'll wipe the floor with Kamala.
Before anyone starts bitching, I know the LGBT community won't turn up en masse for Trump, but as long as Pence doesn't go full fundie at any debates or rallies, I think the LGB will be far more likely to just stay home or maybe vote third-party.
Inner-city blacks are notoriously homophobic even today (although
@Evo brings up a good point that it's not as intense as it was in the 80's and 90's) and this is still very intense within the black supremacist circles. BLM are black supremacist Marxists and they only collaborate with the "queer" community as an alliance of convenience since they have a common enemy right now and because Antifa has a lot of troons and "non-binaries" in their ranks, as well as a smaller but noticeable component of radical feminist lesbians as well.
The T part of the LGBT community are all-in on Antifa, BLM, and communism but there is an increasing sense of resentment among the bulk of the LGB towards the T, partly because of freaks like Jonathan Yaniv and partly because the Woke Left is basically making an entire generation of young people view LGB's as guilty by association with the T and their insanity.
Pence can wipe the floor with Kamala, and the only thing I'd worry about is him accidentally being led into a Kafka trap via the debate moderators or Kamala invoking his religious beliefs to try and get him to say something way too fundie.