well, after some time and around 500 kms there's something to share.

bike is rideable - that's best thing to start with.
clutch was re-assembled in proper order.
also, this time paid more attention on alignment of gears of axle and push rod (these xts' have clutch shift mechanism on the right side). the result is perpendicularity of clutch cable and pull lever (while clutch is being engaged), thus giving the best leverage.
and suddenly clutch gets much softer.
and, more importantly, i could select the gears normally!

from the beginning, clutch used to get slippery, then i had to feed down the cable. some more time, again slippery, bit more adjustment... it happened several times, with quickly decreasing rate.
the reason seems to be some groovy wear on pressure and some friction plates: after re-arrangement this grooves met with flat surface, resulting much less area of contact to wear first and quick.
anyways, already got new clutch kit, now waiting for pressure plate to arrive.

since the assembly, gearbox downshifted from 5th to 4th only once, and one false neutral has happened.
only remaining (or transformed) problem is that now it's neutral to find hard, but it reminds about itself mostly during longer red traffic lights only.

thus, for now the issue is not completely solved, although, it's no more big issue at least.
really didn't expected that proper order of clutch plates could make such essential difference (considering that new oil and better alignment of axle gears are secondary factors).
the time will tell how it will be after new clutch and pressure plate, as well as proper cable adjustments after break-in...

cheers!