It's worth remembering that Lewis was writing for an audience that had a more reverential outlook with respect to Jesus. He's actually relying on the shock value that would be attached to somebody saying Jesus was a liar or a lunatic. Even now we tend to shy away from those two options, preferring instead, to point out that Jesus could have been mistaken or lied about by others.
Correct - and that is one of the most disingenuous/dishonest aspects of the trilemma. Effectively only to provide options which require you to shift to one extreme (bad, mad) or the other (god). And to do so under cultural circumstances where the one extreme options (mad, bad) would have been culturally and societally challenging.
However once you add in the numerous 'middle ground' options - e.g. mistranslated, misinterpreted, mistaken, simply wrong, exaggerated over time etc etc, so are not forced into the extremes - so we are comfortably able to conclude that, based on the evidence, we cannot plump for mad, bad or god.
I think we should all embrace the dishonesty of the Trilemma and and choose "liar". How would Lewis (or Vlad) respond to that? I think the argument collapses completely if Lewis is forced to confront somebody who is prepared to accept one of the distasteful (to him) options.
Hmm, not so sure as this simply plays back into Lewis dishonest narrowing of options. Realistically you, me and basically everyone cannot conclude that Jesus was a liar any more than we can conclude that Jesus was god. Why, well because there is woefully insufficient evident to make either of the conclusions. All we have are writers from decades later (and the actual text we have is from centuries later) claiming that Jesus made certain claims. That is only evidence we have is that those later writers made those claim (as to what Jesus said), not that he actually said any of those things. And what we do know is that the later writers are inconsistent one with another, partial in that they had an agenda and also that there are many, many variations in early copies of those texts. So the evidence (the very limited that we have) points towards conclusions that aren't mad, bad or god.