Here's my perspective as a relatively new player.
I've found mod's to be the most prohibitive aspect of the game for me. I've been regularly farming mods since I could and due to terrible RNG luck I have 3-4 mods that have gone past the +10 point. I'm certain it's mods that are stopping me breaking the top 50 in squad arena consistently as I face so many lesser gear'd teams that wipe the floor with me due to speed. With this in mind I feel there's some both good and bad parts of these changes for me.
1. Lower cost for upgrading mods - good change. Even just for throwing trash mods on pilots this makes it a lot easier.
2. Mod store currency changes (ship credits) - I hate this. I understand it's probably popular with longer players but I've only just finished leveling the core of my fleet. To expand my roster and experiment with new ships will be taking all my ship credits for quite some time. I've given up on checking the mod store because every time I see a mod I want; I realize it's for ship credits and I can't afford it. So although point 1 is helpful; point 2 actually makes it harder for me to get mods I really want.
3. Slicing - I'm optimistic. Due to my bad RNG luck this could be a way to bring some of my poor mods up to a solid standard. Or it could drive me insane. I guess the verdict will come after I see how rare the slicing materials are or if they make any other changes to the mod battles which award nothing of any value right now.
4. Mod management - yes please! All good things here.
5. Removal of challenge requirements - again. Good times for me. Happy with this.
6. Mod energy - All good for me! I have so many cantina farms this will free me up to make faster progress on these characters and still allow me to farm mods without using all my fleet arena crystals on refreshes.
7. 6 dot mods - probably the best way they could have introduced these so that's fine but as per point 3; the rarity of the slicing materials will really depend on how much this either helps or hinders me. I'll have to slice a LOT of mods to keep my fleet arena toons up to speed; which means either slicing crap mods just to 6 dot them or waiting until I have mods worth investing in. Either way COULD be a total PITA but it really depends on what happens with the mod battle table in the end.
TL;DR - These changes sound positive from my perspective but there's still plenty of scope for it to turn out to be horrible. Cautiously optimistic.