grab combos vs. spacies
I thought you're supposed to DI away from backthrow and upthrow? Or is that for forwardthrow?
Also, how do you get away from Falco's downthrow spams/"chaingrab?" I just hold away until I break out, but I figure I'm doing it wrong, because I'm taking like, 35%-40% before getting away. :/
Two questions:
1. How close to the opponent do you have to be when you shine them to Thunder's Combo a character? I'm finding that even if I stand really close to them when I waveshine, I still miss the jab, and I can only really do it when I nair into --> waveshine. Does it matter if my opponent DIs the shine hit away from/towards you?
2. What can I do out of grabs against spacies? I feel like grab --> upsmash is good, but at the same time I think I can do better if I followed up with something else. Against one of my friends, I've done grab till around 20%-25%, and then uptilt x5 --> bair (this guy doesn't like to DI T-T). Idk if this is the right call. :/
So far from testing, you can chaingrab till around 30%-40% before uptilting to a turnaround regrab (assuming that there was no DI at all). Against level 9's, after the uptilt, they DI away, so you can chase and regrab...lolcomputers
Unfortunately, I don't have a real person to test against, so I can't get quality practice in. I've noticed that in vids, some will upthrow and if Falco/Fox DI's away, you can chase nair --> regrab. Not sure what range of percents that'd work at. And what if they DI behind instead?
falco's dthrow sucks
1. vs. falco's dthrow "chaingrab," i hold away and mash shine, this should work every time. you can also buffer roll back which might be useful as well. at higher percents (40%+) i prefer to hold away and dtilt.
thunders is easy
2. your opponent having good DI / SDI on the shine will make thunders slightly harder, but if you focus on having a fast, near full-length wavedash out of your shine you will hit the reset every time. that is until u play zhu cuz he SDI's out of the reset at 7% lol (thunders is way more reliable vs. fox than it is vs. falco)
but yea, even if they have really great DI on the shine, if you do your wavedash correctly you should have no problem hitting the reset (good DI combined with you hitting a max-range shine might make thunders impossible, i'm not sure)
how to grab combo vs. spacies
3. grab combos vs. spacies are actually pretty complex - knowing exactly how to follow-up on a grab takes mastery of each individual option as well as the experience to know which one to use and why.
proximity to platforms, stage position and your opponent's percent are all things you need to take under consideration before you decide which grab combo to do.
things i consider when i grab combo spacies:
a) if they're too low to uthrow -> usmash -> usmash, it's probably a better idea to chaingrab a few times if possible, this will only work on certain stages and only if you are consistent at the CG at low percents. i suck at chaingrabbing so i just uthrow -> usmash and tech chase them.
b) above 55-65 or whatever percent, it's pretty much always better to uthrow -> utilt -> bair (sometimes uair like vs. falcon) than uthrow -> usmash. more damage, puts them off stage, as well as letting you be more mobile after your punish (600 times better in teams btw)
c) platforms are everything - if you're directly below a platform and they will be able to tech before you do your uthrow -> bair, you should either consider bthrowing (good near an edge) or wait for them to tech and then bair them on the platform (extremely easy with fox's speed)
at low percents (<10,) if you grab and then IMMEDIATELY uthrow them onto a platform, it's pretty common for low/mid level players to miss the tech, giving you a free uair -> grab or usmash.
d) if they are at uthrow -> uair kill percent, do a ****ing uthrow uair.
e) bthrow can be pretty good at the edge, i wouldn't recommend it before 6-7%, but after that up until maybe 25-30%, it puts you in an extremely powerful position to gimmick your way into a low percent gimp. people react very differently when they're put into a position like that, so it becomes a battle of the kooks. (expect a success rate of under 20% for this technique because there's about 16 things they can do to avoid dying, but you never know you might guess right!
f) at high percents (90+) uthrowing a spacie on a flat surface (no platforms for them to land on) is very important. if you uthrow a spacie at kill percent, if they choose to DI to the left or right, you can land a charged usmash for a guaranteed kill. if they choose not to DI the uthrow (like a smart player,) you will have to react and go for a bair (or uair if it will kill.) despite the fact that it's common knowledge that DI'ing the uthrow at high percents is guaranteed death, you will be shocked at how many players still do this, basically throwing their stock away lol
hope this answered some of your questions
I actually practice all of the time. I need practice more than other players I know...like if I don't play for a couple days, I am kind of ****ed without a proper warm up. 
