A friend of mine asked me if a deceased's shoes should be disposed of, and if so - why.
Here's where I am so far:
I found that Nitei Gavriel in (Availus vol 1 Chapter 132 pp 714-715) discusses this matter, and basically the ruling is that should not wear the shoes of a mais, but rather dispose of them - because of Sakana (Danger)
As to why specifically wearing the shoes of a mais (as opposed to garments etc) is a danger - the Nitei Gavriel bring 2 reasons:
1) Shoes contain sweat from the feet of the mais (Keter Shem Tov)
2) This could bring about the wearer of the shoes to dream about the mais taking them back... which is a bad sign (as per the dream sugiah in the Gemara Brachot 57b) - (Koret HaBrit)
This probably answers my question, but I'm still not sure I fully understand the above reasons..
also: is the above mentioned danger a spiritual one or a physical one?
There are many Jewish customs that stem from the desire to avoid anything associated with death. See <http://www.chabad.org/article_cdo/aid/1246628>.
<http://www.chabad.org/article_cdo/aid/880152> answers the question more specifically.
This particular custom comes from the Sefer Chasidim, and there are various interpretations as to the rationale.