Nilla marines

I should note this is not all my doing it's mainly things i have picked up from reading other peoples lists and taken onboard what is good and what isn't and made a list out of the ideas that might work well (atleast i think i got the idea of whats good:grin so i hope i haven't poached anyones list if so apologies:blush:

HQ
100 * Libby

Elite
125 * Dread X2 twin-linked auto cannons

125 * Dread X2 twin-linked auto cannons

125 * Dread X2 twin-linked auto cannons

Troops
275 * X10 Marines, Meltagun, Missile launcher,Powerfist, Razorback, Lascannon+TL Plasma gun

275 * X10 Marines, Meltagun, Missile launcher,Powerfist, Razorback, Lascannon+TL Plasma gun

Fast attack
70 * land speeder, Multi-melta, Heavy flamer

70 * land speeder, Multi-melta, Heavy flamer

70 * land speeder, Multi-melta, Heavy flamer

Heavy
115 * Vindicator

115 * Vindicator

1465 * Total

The idea is the marine squads split so 4+1 with the missile launcher in each squad sit back in cover and launch missiles each turn, while the other 4 marines +sergeant with power fist sit in the razorbacks, they both move slowly across the board towards objectives shooting thier lascannons or plasma depending on target priority at the time(one squad has the libby in it too),maybe disembarking to kill squads weakened by fire from other units
The Speeders zoom around killing tanks with MM shots and the switch to flamer for troop killing when theres no more tanks left(if they survive long enough which i doubt)
The dreads pop transports/MC then move on to anything else they can kill thats being a pain
Finally the Vindicators pieplate stuff

I'm not sure of the best powers for the libby to take or what to do with the 35 points i have remaining, so any help would be great, also looking for any tips to make the list anybetter too

Thanks in advance