Hello. I Wonder if there is any detailed information about proces of opening Oblivion Gates. How exactly daedra choose place for gate to form. Some gates spawn at wayshrines or houses, wrecking these in the proces. I Wonder if this happen unintentionally or daedra make it with purpose. So when placing sigil stone in place how they choose location? Any info?

There are a handful of Gates that seem to been chosen for their strategic importance. But I don't think there is any significance to the locations of the rest of them. If I had to guess I'd say Mehrunes Dagon's strategy was simply to "carpet bomb" Tamriel with Gates, overwhelming the mortal population.

if there was any criteria I suspect it was probably similar to Bethesda's: random, fairly evenly spaced and everywhere. Their motives for doing this were probably similar as well: to cause severe mental and emotional anguish.

Good one!

You don't understand my question so well. I'm asking about technicall aspect of opening gates - simply installing sigil stone and what? How exactly they set a location? This is a big mystery.

Some of the information you're interested in, can be learned from the game itself, namely from the book http://www.uesp.net/wiki/Oblivion:Liminal_Bridges.

"...and the mechanic activates the charged sigil stone, which is immediately transported through the liminal barrier to the spot where its sigil was inscribed, thus opening a temporary portal between Mundus and Oblivion.

So it seems the process of opening gate starts at selected spot in Cyrodill, where "sigil was inscribed" whatever that mean, and activating sigill stone in Oblivion World after this. So it seems that destroying a wayshrine was done with purpose. I hope i have interpretated this text correctly.

The significant part is that the gates are opened by the Mythic Dawn at the Cyrodiil end. (And they don't appear to be totally rational). There's probably a fair amount of "where convenient to do so" involved.

The MD have sleeper agents acting as normal citizens all over the place, but they take a major risk by revealing themselves. The targets that would make that worthwhile are the Emperor and his family before the acquisition of the Amulet, and Martin and his known associate (the player) after. So Bruma, which is known to be close to Cloud Ruler Temple, has spies and special gate treatment. Gates are opened wherever the player goes in hopes of ambushing/entrapping him/her.