Well lets start with stellar neighborhood. The average distance between stars is so great that planets will be influenced virtually entirely by the star they orbit. That is true pretty much everywhere in the milkyway save for the very central stars.
Most of the time this true, but it's the potential for close encounters that can be disastrous. It is hypothesized that even distant encounters can wreak havoc by triggering a maelstrom of infilling cometary material.
Star type: The sun is an average main sequence stars, plenty of those.
Well actually the sun is pretty big for main sequence (~ top 10%), but you can't simply treat a main sequence star as the light bulb you let you planet nestle up nice and cozy to and everything will be merry. Stars are giant dynamic furnaces and there are plenty of examples of stars exhibiting swings in luminosity, especially while they're young. Stars also change luminosity as they age, perhaps causing formally habitable worlds to become uninhabitable. These issues have the potential to exclude a lot of stars!
I think this naturally goes with world orbit btw if one is concerned with creating the right temperatures. Taking a look at the solar system with Venus Earth and Mars it seems that we have some play here.
But that's not the whole story! Orbital eccentricity comes into play here. Most discovered planets have much higher eccentricities then Earth's. Temperature variation is certainly an effect of this. Another issue is stability, Earth's eccentricity slowly shifts around but remains within a small range of values, but other planets may not (in fact Mercury is an example), so even if they are not eccentric now, they might have been earlier.
World chemical properties: Well, we can measure spectral lines of stars and we have models for nuclear synthesis. I haven't heard anything indicating a trend in our vicinity. Obviously only an indicator though.
That really doesn't address the issue though.
Other solar system bodies: Large gas planets similar to Jupiter have been observed. Apart from catching meteorites I'm not sure they have any influence though.
Cathing meteorites, spawning meteorites, orbital impacts on the planet itself.
Baring a reset button along the lines of K-T, why wouldn't intelligence be a trait favoured by evolution?
Well, intelligence as in just generally getting smarter, sure that would probably be favored, but intelligence of the human sort, probably not as much. Human intelligence, is extremely costly from an evolutionary perspective and requires a unique environment for it to come into place. Wolves might get smarter, but it's doubtful that they'll grow opposible thumbs and make rocket ships.
It really depends on how we define common. Fermi's Paradox assumes some things about scale of which I'm very skeptical. If there's another civilization within 1,000 light years of us, I'd think of that as life being common, but we'd have a very hard time detecting one another.
Well, some of the magic of the Fermi paradox comes from the longevity of the galaxy. Consider if there were 10 intelligences out in our galaxy (far less dense then your suggestion), and each lasts on average a million years, then in the past 2 billion years there should have been about 20,000 civilizations, Why didn't a single one of them colonize the entire galaxy (which presumably we'd detect)? If it was as you proposed, then we're taling 2 million civilizations, not one of them which managed to pull off the feat. And that's not taking into the account the potential for civilizations in nearby galaxies to pull off the colonization in ours. We are ingenious spreading machines, that I believe are fully capable of colonizing the entire galaxy within a few million years a split second on the timescale of the galaxy, and yet we don't see that that's happened. That's the core of the Fermi paradox.
Of course not, if you look at things at a small enough level, they're too chaotic for any two things to ever be exactly the same. But they can be pretty damn similar.
They can be similar, but are they similar enough. Say I take a casting of my rock to use as key to secret shrine to Fifty. Those rocks that were very close, might still not be good enough if I have a fairly precise casting. The sme might be true of chemical environments, it could be that forms near that needed to start life don't do anything at all and only the exact rare combination unlocks the power of evolution.