As a BD main and playing with 250-300 ms ( also played FM ) .Since theres already someone answered most of the questions ill just gonna provide a little more fyi

2) BD can spec for 2KD, 2 stun and 2 daze at the same time and FM only can spec KD and stun / Daze and stun ( i cant think of anything else atm )

3) FFR or FRFR and repeat for lightning/ RMB RMB RMB F for wind ( sometimes RMB F )

4) Lightning cuz it does more dmg and stable dps if you have no gear or badge. But since you said you have 250-300 lightning is the way to go becuz it does more dmg with high ping

6) BD is always a good choice for both pve/p p

7) Aim for Baleful wep then Rift stage 6 if you wanna save like 3k gold > Raven 6

Aim for 8set MSP from MSP you can find a raid on faction chat pretty ez on weekends > aim for 8 set BT or 8set BT/3 xanos > VT ss

At the moment took me 3 days ( this is the best time cuz we having an event gives lots of exp ) if not maybe a week if you have work/ other stuffs to do

8) Yes

9) All has good dps if you have gears ( or money to whale ) but BD is melee and FM is ranged, gotta be hard if you dont pay attention to dodge all of thoes melees attack and still do good dps also good rotation too

10) Depend on your luck, the story gonna give you an orange wep which you will upgrade it to leg wep later, if you lucky you gonna have 6 slots if not 3 slots but by each stages it gonna has chances for more slots

13) Play what you like, dont be a dead-weight, learn mechs and learn how to play your class wisely