What skills do I need as a Remote Sensing Expert?
That's a bit more complicated question to answer, but let's try to put everything in place.

A remote sensing expert is a person who is able to perform processing methodologies on data (mainly images and in-situ measurements) and extract meaningful information from these data in order to feed business (and technical) decisions.

That said, let's try to make it a bit more specific:

√ - Mathematics and linear algebra

√ - A Programming language like R or Python (imagine it as a tool assist you, not as the purpose)

√ - Specific remote sensing software (ENVI, ERDAS, ORFEO, SNAP, QGIS, GRASS, etc)

√ - Understanding of the domain specific you want to work for (e.g. Agriculture)

Source: Geo university.