Hey @Kkbbth,
Welcome. You've had some great info from everybody already.
I had full axilliary clearance with 5/24 nodes positive. ER PR pos Her neg. I have never needed to use any preventative things on my arm. I just did my exercises religiously plus more. It has been 18 months since my surgery and I have zero problems with lymphodema and full strength back in that arm for a long time. It does make you a bit protective of it at the start I know but that will wear off.
I did my chemo without a portacath all infusions and weekly blood tests done in the other arm with no real issues. However there was no surgery to that side.
The chemo appointment is pretty daunting and scares the heck out of all of us. Keep in touch. We all "get it".
Your kickassery (love it) will help you through. :)
xoxoxoxo