Questions about upgrading mk3 to mk3s  

Questions about upgrading mk3 to mk3s

I got my MK3 in March of 2018, and early on I had tons of issues and had to replace much of the stock prusa hotend parts more than once. First the entire hotend assembly, and later on the nozzle, heat break, thermal paste, and ptfe tubing with more durable Microswiss and Capricorn parts just to be able to print reliably, it took months of daily hardware troubleshooting on the old forum and there were many helpful suggestions. I've seen the MK3s upgrade kit in the shop and after looking at it I have questions about it before I decide to upgrade, as it took me months of work to get my printer to its current working state and I want to make sure of all the details first before I make changes.

1.  It says it comes with a spool of PETGE for self printed parts, does that mean I'll need to print parts for this kit ahead of time before I disassemble it in the current state? Using default settings in Slic3r Prusa edition, I have had major issues printing anything other than PLA with my printer, and have only been able to  partially print small items with higher temp filaments by using extremely low detail, custom gcode settings I found on the forum to print as fast and simply as possible as the default settings just don't work for my printer. I'm worried I won't be able to print those parts, can they be ordered?
2. From reading the contents of the upgrade kit, it looks like the ptfe tube is the only difference in the hotend assembly. I had to install a custom microswiss plated wear resistant thermal tube between the heat block and heatsink as the stock Prusa one had problems even though I only use PLA. So I shouldn't need to replace anything with my current working hotend besides the ptfe tube, correct? I also use capricorn tubing as I've had issues with Prusa ptfe tubing twice in the past, I am hoping I can continue to use that, just cut it down to the new size and bevel the edges.
3. Since I got my MK3 so early on and I know they released changes to the extruder fan and maybe some other things since I got my printer, my current assembly doesn't look  like the disassembly instructions for the upgrade kit, Will this be an issue?
4. On the MK3S shop page says the MK3S has 2 new thermistors, and a new PINDA 2 probe (this one has a black tip while mine is the original PINDA and has a sort of cream white tip). The upgrade kit doesn't say anything about including the new PINDA sensor. If I don't have a PINDA 2, do I need to buy one when upgrading? In the shop it says it's only compatible with MK3S.
5. Will I need to re-slice all of my current print files and specifically set them to MK3S in Slic3r? I sell models with 50+ printed parts each and I've been using the same files for over a year. Will they need to all be re-sliced and changed from MK3 to MK3S with new settings?

Thank you very much for any questions you can answer, even if you can't answer all of them.