Learn English – Does “somebody of the caliber” mean the speaker themselves

everybody gave them the road, and took their ribald insolences meekly, without venturing to talk back

Gave them the road is not an expression that native speakers of my part of the U.S. would say, so it seems outdated. As a speaker of 20th-21st century English I would interpret it to mean something like

everybody yielded them the right of way

which means, everybody got out of their way and let them pass by or whatever.

There is idiom in Cassell's Dictionary of Slang give someone the road meaning to avoid, to ignore and another entry for the same ohrase that is an alternate version of give someone the bag. When you look at that one (p. 603), none of the definitions really fit. The date given for the first entry (avoid, ignore) is 1910s+, which is weird, since Twain published P&P about 1880.

I am not sure how well ignore or avoid fits here, since the passengers also took their ribald insolences meekly, without venturing to talk back. Maybe one of the things they did was to avoid or ignore them. This definition seems to fit, and again the phrase give someone the road is not used today in my experience. But avoid can have a meaning of yield someone the right of way.

Whatever it means, it means to try to stay out of their way. Sometimes native speakers have to guess too.

It's simply idiomatic.

the hell out of
very much:
You scared the hell out of me!
Note: This may be considered offensive by some people.

So in the OP

... will most likely annoy your visitors very much.

This version is polite. The original is somewhat crude but feels more emphatic. For instance, imagine that you are a visitor to that page and you become very annoyed (pissed, in American slang). If you have no problems swearing (hell is a mild swear), then you might say this page is annoying the hell out of me! [= This is really, really annoying me!].

Note that the meaning the hell out of can differ depending on the context.

—— the hell out of
informal
Used in verbal phrases to emphasize force, speed, etc.:
'let's get the hell out of here'

This would mean let's leave fast/quickly.

One more example: Dad Trolls The Hell Out Of His Daughter’s Selfies

Here, the meaning is something like dad thoroughly makes fun of his daughter's selfies or dad does a good job of making fun of his daughter's selfies.