None of the Components—Verbal, Somatic, nor Material—are required for these spells
In the Player's Handbook, in Chapter 10, Spell Components are explicitly described as encompassing the Verbal, Somatic, and Material costs:
A spell's components are the physical requirements you must meet in order to cast it. Each spell's description indicates whether it ...
Yes, as long as the spell doesn't require any of those things.
The official wording of the trait says:
As a bonus action, you can magically turn invisible until the start of your next turn or until you attack, make a damage roll, or force someone to make a saving throw. Once you use this trait, you can’t use it again until you finish a short or long rest....
When reincarnated you do not reatain ability score improvements from your previous race
Since your racial ability score improvements come directly from your race's nature, if anything changes your race, whether reincarnation, polymorph, etc. your racial ability score improvements will change just like any other racial trait
You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift
Grappling is defined as a Special type of Melee Attack that can be used to replace one of your Attacks as part of the Attack action.
The target of your grapple must be no more than one size larger than you and must be within your reach.
RAW is unclear
No you couldn't
Natural Armor (VGtM p. 113)
You have tough, scaly skin. When you aren't wearing armor, your AC is 13 + your Dexterity modifier. You can use your natural armor to determine your AC if the armor you wear would leave you with a lower AC. A shield's benefits apply as normal while you use your natural armor.
Defense (PHB p. 72)...
If you are playing Adventurer's League, then yes, during the current season (9) every Aasimar and Tiefling can trade in specific abilities for the flight ability. The Aasimar loses the Light cantrip and the level 3 ability, the Tiefling loses the Infernal Legacy (or replacement) trait, but they get permanent wings in return, adding an innate flying speed of ...