what happen if i added nodes to my list which are not the of same version, are they skipped ?

do users of different version can connect wich each others, if no wich version have much users?

why the list nodes is so frequently refreshed, do the old
adress nodes become obsolete or are they simply supposed to be a bridge in some way for new users ?

at hashdb.com why the hash isn't working for share, is it in another format, if yes is there a converter or is it working simply destined to work for another jap p2p prog if yes wich one?