Please keep in mind that if your 'ufo' has a red light on the left, a green light on the right and a white one at the rear, it's an aircraft of some kind, regardless of how many strobe lights may also be present. Xenon strobe lights have become very popular as anti-collision lights and have been causing some UFO reports. Also note the 'standard color scheme' for running lights varies from one country to the next.
As for ETs wanting to be seen... that would depend. One item to consider is that the act of observation tends to affect whatever is being observed, so it stands to reason they'd want to be as discrete as possible and make as little impact on our development as is practicable.
I would assume that such observations would be to determine how much of a threat man represents to alien species, given that man is by nature xenophobic, paranoid, violent and superstitious.
Man as a race possesses short range space flight, orbital devices of various types, nuclear propulsion, atomic, projectile and beam weapons (laser, maser, etc.). With a few modifications, a modern submarine can easily become an armored spaceship. We've devoted a lot of media to killing evil aliens and we're very good at warfare. It would be foolish to believe, if there is intelligent life in or near our sector of the Milky Way, that aliens aren't observing us.
I'll bet that within a week of aliens publicly visiting Earth, some idiot starts selling bumper stickers that say 'Welcome to Earth, now go home'.
Humor: 'This message has been brought to you by the Mars-Sirius Coalition for Domination of Sol IV.'