Status Immunity questions

1. Do haze bombs require 7 points to be immune to and whisps require 9?
2. Does a black kat raiment with shock max and a Crown of the Fallen with shock max and a 5* shock resist trinket give +9 immunity?
3. And will a full fallen set give poison and fire resistance +9 if one piece has poison low and I'm equipping a grand solstice ring?
4. And will full black kat give +9 freeze immunity if I'm equipping a grand solstice ring?
5. Does a grand solstice ring have +1 freeze and fire resistance?
6. Does a 5* status trinket have +3 points of resistance for its respective status?
7. How about moderate status? Can I be immune to it? How many points does it require to be immune to it in both PvP and PvE?

Can you even be immune from say status guns in LD? Like pulsars and alchemers? Also I remember reading about that +10 resistance does something special but not entirely sure, what does it do exactly?
i believe u need max max low for moderate (gun status)

Yes, you can be immune to moderate with +8.5 (whisp immunity). Nothing is special about +10 except for it being the cap of how much status resistance it's possible to stack up. Any more, and you'd also be immune to strong status.

Isn't it impossible to be immune to strong status? Also what's the practical cap of resistance, where you get the most benefit?

Yes, it's impossible to be immune to strong. That's why any resistance above +10 is impossible to achieve, (even if you stack up a quadruple max, +16, it'll only have the effect of +10). This remains true until such a time that weapons/enemies start inflicting statuses stronger than strong. If something was in theory capable of inflicting 8-strength status (double strong), then resistances up to 14 would have an effect against those. I estimate this to happen somewhere between "never" and "when all the armours in SK become balanced" (double never).
Your other question is more difficult to answer. Any more than +10 (max + max + med) gives no return at all, +6.5 and +8.5 are sweet spots because they provide immunity. For any resistance beyond 8.5, the effect is negligble for all statuses. You won't protect any more slots from curse, or take any fewer ticks from fire. The only difference will be a few less points of fire damage, curse damage, poison debuff-ness, etc. Small changes.
1. Technically 6.5 and 8.5
2. Shock max is 4,Kat gives -2, Crown doesn't affect shock, trinket is +2. 4 + 4 - 2 + 2 = 8.
3. Yes
4. Yes
5. Yes I think so.
6. No, it's +2. Sprite perks will give +3 though.
7. +8.5 is moderate immunity.