How are raid rewards determined?
Pokémon GO Raid rewards are determined by your raid performance, the team controlling the Gym and the rank of your Gym Badge. It’s not yet known how these aspects affect rewards, but it is known that they do.
Can I use a TM multiple time on the same Pokémon in Pokemon GO?
Unknown at this time. The official press release states that these changes are permanent, but it’s yet to be seen.
Are raids soloable?
It depends on the Difficulty of the raid encounter. Some raids are, some aren’t soloable, but it’s expected that the majority of raids will not be soloable.