Amatuer sofer here with 2 Q's on M''B!
1) 32:32 - Above each line one should leave enough space for the top of a lamed (which is a vav..so 3 kulmusim).
After that shulchan aruch the rama says to leave "bain hashitim kimlo shitah".
Is that referring to the same thing as the shulchan aruch. If not - the MB says that "the sofrim" arent noheg to leave a "kimloh shitah" for teffilin and mezuzos etc....So if the rama is referring to the additional top of the lamed (which the m''b said not to do by mezuzos), how would you write a lamed in the mezuzah?
2) 32::78 - m''b says that if letters keep their tzurah but touch, just remove the connection and it's kosher..whether before or after writing. Seems quite clear!
143:25 - If the connection is in the beginning of the letter, even though there's no shinuy tzurah but "the rest of the letter was written bifsul" (which from my understanding of 32 means u have to rewrite it).