I'm loving the mod! It really pairs well with Strategia, which I also discovered recently.
One thing you may want to take a look to, though: DMagic Orbital Science contracts seem to give A LOT of money and HUGE amounts of science for the early game. Example: A single repeatable Mun magnetic survey contract gave me like 80 science in total and more money (advance + reward) than any of the Mun milestones from PBC's contracts. I'm pointing this out since it is listed as a supported mod, and the slower, more balanced progression is what I've been enjoying the most from PBC.
Guided by your recommended difficulty settings, I have set my reward multipliers on a mid point, and it seems to be just right for both PBC and Strategia, so lowering that to balance those rewards is not an option.
Other contract packs that imo were too OP (although not listed as supported, so this is more like a suggestion) were CleverSat (gives too much funds) and CommNet Relays (gives too much reputation).
I'm glad to help with this if pointed in the right direction, as I'm a newbie in KSP modding but have experience with modding/tweaking other games.