Small amounts of light are visible in the front vents. However, the projector throws no significant light out those vents. Not an issue. No ambient light outside the projected area coming through the lens (sometimes a minor issue).
Take your pick. 2D, as with almost all projectors is rather clean. Let's put it this way, any image noise you are likely to see, is less than the noise of compression when watching HDTV content. Standard background noises are not as noticeable as with a typical DLP projector (which is the most direct conpetition). 3D is really good. It seems cleaner than several higher priced projectors. Consider, though this is an entry level 3D capable projector, and in that sense, 3D related noise, be it crosstalk, etc. should be treated as a non-issue, considering it rivals easily first gen 3D projectors (most still shipping) costing 5x more.
Definitely this Epson family room projector can make a bit of fan noise with lamp on full power, but really no more than the competiton. Cut it to low power, and the Home Cinema 3010 becomes relatively silent, with a claimed 24 db, far quieter than most dedicated home theater projectors at full power, and as quite as many of them even in eco mode.
When the Epson is cranking out lumens in full power, Epson says 32 db audible noise, which is fairly typical of competing (mostly) DLP projectors, and a touch noisier than Epson's own 8350 and 8700UB models. Considering that you will probably be watching movies in low power (other than 3D), no issues there, and even if you run at full power, it's in line with competing Optoma brand and other DLP projectors. For example, the most direct competition, the Optoma HD33, is similarly noisy when both are at full power, but the Epson is brighter at low power, than the Optoma at full power!
I currently have two Home Cinema 3010 projectors here, the first an engineering sample I received a few weeks ago, the second one, a far more finished projector. That first unit raised some concern. It had a dynamic iris that as physically rather noisy when operating, "clickity, clackity" at times. I immediately noted that to Epson, that it seemed loud enough to be a problem for many folks.
Even at that time, they assured me that they were aware, and that the production projectors would be far quieter in this regard. As it turned out, they were dead on. The iris on the second unit still clicks and clacks, but not near as often, and far, far softer. I definitely don't think the iris, behaving as the production units should, is even any noisier than the rumbly iris of the Epson 8700UB and the UB's before it.
The soft occasional "clickity" you might hear from a few feet away with the sound off, is certainly going to get lost with the slightest audio, be it talking or music, never mind "action" sequences. I'm sure there will still be a few who are bothered by it, as there are for almost every projector, but, certainly, for a family room type projector, Epson has reduced it to a non-issue.
In other words, this Epson is definitely about as quiet as anything else out there targeted for family rooms, etc., and is actually about as quiet as the average (not the most expensive) DLP projectors designed for dedicated home theaters. This Epson is going to be slightly noisier than the average LCD projector targeted for dedicated rooms..
Bottom line: Lots of lumens, but very respectable noise levels. Normally very high brightness projectors have hotter lamps, and need bigger/louder fans. All considered, a real good job.