Choosing free software is actually not difficult, but many people believe that it is. This can become a self-fulfilling prophecy, causing miscellaneous problems.
Here are some examples of the challenges you are going to face:
Psychological effects (“Under Windows it would work better”) ranging from personal reproaches for your decision to measurable side-effects.
When using free software, it is more difficult to get professional support, trained human resources, specialized hardware.
The end-users themselves use proprietary software at home and are reluctant to change their habits.
Free software cannot serve as capital. While this is the inevitable condition for remaining free, it also reduces the motivation of investors whose primary goal after to make money.
A widely spread attitude which I use to label “Uncle Tom’s Advice” is to say “Come on! Stop making your own life complicated, we are all slaves of somebody, just let Microsoft or Google or Apple be your master and enjoy life!”.