tea and mezuzah follow up

Question

a)this is an excerpt from lipton website I don't know if this counts but it should because "ein bishul achar afiya" also I am not sure it applies to all teas : At the proper moment, the leaves are dried under high temperature to seal in juices and flavor. This causes the leaves to turn black, hence the name "black tea." Oolong tea undergoes the same process as black tea, but the oxidation time is briefer. Typically, the taste of good quality oolong tea is peachy and mellow. b)to clarify tea bags are kalei habishul or not? (you said "we dont say kalei habishul on just anything") and therefore can they be put in a kli sheni yad soledet bo? c)as far as mezuza questions, is there anywhere else to look because shulchan aruch does not say very much. I take it from your answers that almost any room "daled al daled" needs one even if not used for living in the room. Also what is the modern measurment for daled amot that we go by. Thanks again, Henry