beta testing on the assault marines w/t out jumppacks. when i was younger i decided to make one. And with me i have about a 75 percent win rate with them.
The reason that they are good in my matches is because people tend to overlook them, but what they also overlook is the fact that i have a chaplain on the inside with them (i have to run them in a crusader because that is the only thing big enough to carry eleven models) but with the chaplain and one of his special rules, i get to re-roll all failed to hit attacks on the charge. ten marines with 2 attacks and then an extra on the charge is 30 attacks along with the five i get from the chaplain and his power weapon, not to mention their bolt pistol and plasma shots, and the shots from the crusader at rapid fire range. with that being said, their are very few squads no matter what size that can survive a tidal wave of shots and then an all out assault re-rolling hits, and all for the same price as a regular tac. squad, i think of this squad as a diamond in the rough. there are very few squads that can stand on an objective and survive this. with that being said i would most definately recommend getting one of these squads. I made mine out of the blood claws ten man space wolves box.
On the other hand comes your questions about the LR and vindicator.
vindicator all the way without doubt you need one, and considering the fluff behind your army it is a great choice.
LR- i stand a little torn on the land raider specific choice i.e you need one without doubt but the LRC or the regular LR, the LR is basically your most prized possession in a match simply because everyone knows if it isn't killed it will kill, so you basically have a huge target floating around the board and has the best armor all the way around n the 40k universe, so people are trying to kill this whilst the workers go around the board almost untouched. now i am torn because the crusader is a great choice whilst assaulting an objective, but what happens when you get an annihilation mission, then the LR is the better choice simply because you have an awesome tank buster that can sit back and shoot across basically the entire board, and if its in cover now the best armor in the game can roll a 4+ and be perfectly unharmed. So there lies the dilemma. But if you have a good dreadnaught... then your in good shape.
so leads us to the dreadnaught situation. you have a crusader and your in an annihilation match, well if the dread is a venerable and has tank hunters on it the your lascannon now strikes at strength 10 and your missle launcher is strength 9... wonderful now your crusader goes headhunting for the troops and your dread pops all the baddies that threaten your vindicator, and your vindicator can go around killing all the TEQ's
So thats my piece on where you should go with the crimson fist, hope you will post some updates.