Paying with property wild cards, can they be placed anywhere?
Yes. Property cards - including wild cards - can be arranged however the receiving player sees fit, at any point during their turn. For two-colour wildcards, there is no restriction that these have to remain in the orientation that they were originally played.
Note that ten-colour wildcards have zero monetary value so should not be used to pay rent -see Property FAQ points 3 and 4 on monopolydealrules.com.