Played more Crusader matches, I retract what I have said earlier about its weakness. It can and will affect the outcomes of the matches. From initial scouting, to supporting the entire map to shredding opponent's armour, there is nothing I can't do with it. Just enough speed, adequate mobility, good gun depression, insane rate of fire and the stealth of a passive scout, anyone is a target. If I am playing at top tier (with lots of tier 4 and a smattering of tier 3) then its a "shoot the ducks" game. Against tier 7 opponents it can still dish out a lot of punishment to unsuspecting opponents on top of cleaning the battlefield of go karts and arty hunting.
Fourstaff's miniguide to Crusader:
1. Scout to halfline, and make a fast retreat. Make sure you don't get hit, so if you fail to see anything don't worry it means there is nothing there.
2. Drive around in circles between the half and third line, pick off the suiciding scouts.
3. Mediums and lights would have already start their initial skirmish: this is the hardest part. move close enough to give a shot or two, but make sure you don't get shot at all cost. Being the receiving end of a shot will almost certainly mean a broken module or a dead crew, dead commander is fine but a dead driver/gunner will cause massive problems. Heal those two asap, repair gun/engine if needed. Damage to the rest like tracks or turret is usually non critical.
4. Heavies arrive and start slugging out. If you have survived this long mostly intact (no module/crew damage, 1/2 health gone, etc) then you are in a good shape to finish the game at or near the top of the list. Support as necessary. This will mostly involve sniping from ~200m, then scooting off to another part of the map to support that flank.
5. While the heavies are busy peekabooming, the mediums will be trying to flank and such. This is the golden time to find a gap, slip through and wreck havoc on the back lines. Not all maps are suitable for this, but if the opportunity arises you should take it. If there is none, continue sniping and doing general annoying things. Don't worry about non penetration, your opponents do not know what hit them, and will be more cautious/annoyed than they should be. Make sure you don't spend too much time doing this, precious dps can and should be used elsewhere where your shots actually go through and translate to damage.
6. Cleanup. Self explanatory, if you managed to punch through and wreck the TD/arty line then its just shooting heavy from behind, if you are still within your team's control zone, then its just zooming forward and cleaning up everything else. Very few TDs can keep up with your circling, so don't be afraid to engage lone ones.
Equipment:
Camo, rammer and either vents/EGLD, binocs, or equipment of choice
Crew skills:
your favourite, although 6th sense is very much appreciated. I find the tank already capable enough not to bothered with things like off road driving, smooth ride etc, but they can be used to for even better handling. Make sure the crew skills line up with equipment, eg camo training + camonet + binocs, vents+BIA etc.
Lastly, if you get the attention of one or more tanks, just sit behind cover and let your teammates mop them up. if those tanks decide to change target, pop out and give them a shot or two, when they turn back to face you go back to cover. As a corollary, make sure you move in such a way that when they decide to come out and hunt you down, your teammates will cover you well enough that you should at most receive a shot before the suicidal tank retires from the battle. Similarly, if a derptank is bumrushing you, make sure you use your 21kph retreat and pray his shot misses.
Edit: so what about losing matches?
You can't do much if your team decides to do a lemming rush. Just make sure you cover the undefended flank long enough for the lemming train either to force through with the sheer amount of tanks, or fail miserably. As usual, move to the 1/2 line, but this time stay close to that. Take a shot at the lead tank, and then make a slow retreat from cover to cover. Standoff (both sides sitting behind cover and not shooting) as long as you can. Because your opponents will be focusing all their attention on you, there is a good chance you will die before long.
What if the opponent is holding an advantage and slowly building on it?
This is where the Crusader shines again: the ability to whittle down that advantage. Overconfident opponents with advantage will usually play a bit more aggressively than they will normally have, providing ample opportunity for you to whittle down their health and numbers from relative safety. A game changer if you ask me: KV1 can only derp one vehicle before he gets swarmed, whereas the Crusader will just slaughter the weakest, and then make a quick retreat to the next safespot to pick off a few more. It will not be unusual for a Crusader in a team down 10:5 to pick off at least 4 opponent before going down, provided the surviving ones are not armoured beasts.
Actually thats wrong because some tanks are just simply better than others, usually it's the tanker that makes them bad.