Question can i update my ultra to 4.4 ?

hi all

i bught droid ultra limited unlock gsm from ebay / and now it work perfect in my carrier in my country . in asia

i have quastiones :

phone is for ever gsm unlock ?
can i update to android 4.4 ?
is this possible to phone be locked again after update new rom ?

please help me . i affried to update or change my rom :
motorola for ever
my moto phone history : v3-- v3x-- z8-- z10-- e6-- l6i -- zn5 -- wx180&181-- xt502-- xt720-- defy -- ex115--- backflip-- v8 gold ---atrix --razr xt912- defy plus --- cliq xt --- sony xperia s --- atrix hd ... razr hd .... razr i .... droid ultra limited edition . ...

what is next !? ((:

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