I'm assuming you have/are applying for a job with an electrical contractor. I answered my questions based on that assumption.
Every contractor/company is going to have different requirements for their BIM/VDC Modelers. Since everyone hasn't adopted Revit in the same way. I worked for an electrical contractor for almost 8 years.
I can tell you that I personally never had a typical day. It just depended on what project(s) I was working on and what needed to be done. I was either modeling/coordinating, reviewing drawings, talking to the field, working with prefab, answering questions, etc.
For the most part I was in the office every day, but we did visit sites. Also some modelers did work on site, but it was rare. I do think it is becoming more desired by the operations team.
The layout was sometimes handled by me and sometimes worked with the foreman. Just depended on the job and the foreman. If the foreman was involved it was usually just a rough idea of what they wanted since coordination can change things. *This only works though it you know how to route/group/size things correctly. Plus having at least a general knowledge of the Electrical code.
I had to focus on the construction as well as prefabrication. Although if you do it right they both tie together. It just takes some coordination on your part to make sure that the field knows what is being designed/built in prefab.
I started fresh out of college with basic electrical knowledge. I was luck and was put on a large hospital project when I first started and was able to work with long time electricians to learn the best way to route conduit/code/things not to do/etc. Then from there just built upon what I knew. I've worked with individuals straight out of college and guys who've worked 20+ years in the field. What it comes down to is realizing that in order to have a successful project you need the technology skills as well as the filed knowledge. Having just one will never work.
We used Trimble and TopCon. I created the points from the Revit and sometimes AutoCAD plans and provided it to the individuals in the field laying out the points. There will always be some sort of problem with these files. Something doesn't line up/ show up/scale right/etc. Just have to troubleshot and figure it out.