Like your BBLog assignments - here are some more ideas:
1) my 50 bucks - Get 50 Master Dogtags (500 Kills) with weapons

2) Weapon class pro - get all weapons within a weapon class to one service star (without Dice only weapons)
--> could be done for every weapons class (carabiner, shotgun, PDW, light MG, Sniper rifle, assault rifle, explosives (RPG, AA, Mines, Grenades), pistols)

3) Weapon class master - get all weapons within a weapon class to 5 service star (without Dice only weapons)
--> could be done for every weapons class (carabiner, shotgun, PDW, light MG, Sniper rifle, assault rifle, explosives (RPG, AA, Mines, Grenades), pistols)

4) Weapons Master - get all Weapons to 500 Kills (without explosives and Pistols)
--> could be done for explosives/Pistols as well

5) real Jack of all Trades - get 10 Service Stars with all 4 classes

6) Weapon God - get any weapon to 100 Service Stars

7) Vehicle God - get any vehicle to 100 Service Stars

I hope you like it :)

OK - some more ideas you might not have had yet :)

- Watching your back - get 25 Savior medals (or 5000)
- Redeemer - get 25 Avenger medals (or 5000)
- sharpshooter - get 25 Accuracy Medals
- Mr. Invincible - get 25 Combat efficiency medals
- Teamplayer - get 10 ace squad medals
- Dr. - get 10 medical medals
- Spy - get 10 surveillance medals
- Conqueror - get 10 flag attacker medals
- Defender - get 10 flag defender medals
- Helping Pro - get 10 resupply, maintenance and medical medals
- Destroyer - destroy 5000 vehicles
- Headworker - 10000 Headshots

then you can mesh them together:
Teamfighter - Get 5000 Savior and Avenger kills
Spying Sharpshooter - get 10000 Headshots and 10 surveillance medals
Flag Man - get 10 flag attacker and 10 flag defender medals
Battle Pro - get 25 combat efficiency medals and destroy 5000 Vehicles
Helper - get 10 resupply, maintenance and medical medals

You are right - makes it more demanding :)