The only problem my be if “addr:street:sr-Latn” is correct syntax.
Yes, see above.
a) Data redundancy is a bad idea on many levels
b) We really don’t know how search works and if it’s really neccessary
This should be shifted to the main project list, nothing will be resolved here. See e.g. others suffering from multilingual issuses:
http://gis.19327.n5.nabble.com/Re-Talk-hr-Names-of-towns-in-Istria-td5713372.html
The way I see it, the name tag is used for a street, house, object, mountain, river, rubbish bin… It does not necessarily conform to the address search requirements. Whereas each and every object can have an address, no matter if it is on a street or not, in an urban area or not. Therefore, although the data might seem redundant, I feel that it just happens to be on two completely separate layers.
Maybe. In any case, a clarification of that view on the main OSM list would be helpful.