Then, move the MegaMaid into an orbit around Mars and go from suck to blow. Venus has too much atmosphere, Mars has too little. Win Win.

It wouldn't do Mars any good. Lacking a magnetosphere, any atmosphere you add will get stripped away by the Sun.

I’ve read that a large asteroid could be positioned at a particular Mars L point and it would protect the planets atmosphere from being stripped by the sun.

I've read something similar, but I believe it has to be an asteroid with a magnetic field, whether permanent or electromagnet.

The estimate I heard is it would take 100,000 years for the atmosphere to be stripped off. That’s a long long time.

The atmosphere will be stripped away over a time period of millions of years though.

Something like a solar powered space elevator that just blows atmosphere into the sun

That would require a lot of energy to ensure the gasses escape Venus' gravitational pull, which would in turn effectively be a rocket. So then we'd be adjusting to ensure we don't mess with Venus' orbit too much.

Venus outweighs its atmosphere by about 10,000 times. This is actually less than I thought -- for comparison Earth outweighs its atmosphere by over 1,000,000 times, which is still far less than I would have guessed.

Venus's escape velocity is less than 1/3rd of its orbital velocity. According to google, Venus's orbit, despite being very circular, causes its velocity to vary by a KM/s from aphelion to perihelion.

So I believe you could send all of Venus's atmosphere off permanently into space at the cost of about 1/30,000th of Venus's orbital velocity, meaning you could very slightly circularize its orbit further.

Spinning it up would be handy.

We can avoid orbital drift through the magic of building two of them.