migrating to python from R: specific questions
1) Anaconda Spyder, maybe

2) sklearn, random forest has an option to select the number of jobs, and it will take care of parallelizing

3) i don't think so, but you can pickle objects and load them up. you can probably do something like create a variable_name - value dictionary and just pickle that

4) never tried

5) according to https://stackoverflow.com/questions/21288133/loading-rdata-files-into-python, I don't think so