"The Hive", Guard vs. Tyranid scenario

Inspired by a conversation between myself and Mike(see the link to his site over in the links box, down yonder ==>),which basically established that all our 40k games are like Starship Troopers in table top format. Which leads me to this:
"The Hive", a Tyranid vs. Guard scenario. These are the first test rules I'm going to set up, and they will be modified based on how they play out in test games.

SCENARIO:

Army Compostition:
The Tyranid player fields a 3000 point army, however, they may only field one HQ, and any models with the "Infiltrate" "Scouts" and "Stealth" special rules will be considered to not have them, and units may not deep strike or be held in reserve.

The Guard player fields a 2000 point army. Additionally, one unit of Conscripts may be taken independently of that 2000 point force, using rule "FOR THE HOMELAND" (see under "Scenario special rules, further down.)

Fluff:A tyranid Hive-Ship has been shot down over the skies of your homeworld. The Imperial Navy refuses to waist ammunition on destroying it for good, and the nearest Ordo Xenos Deathwatch marines are engaged in boarding actions in the space battle in the heaven above your world. It is up you and your fellow PDF troopers to finish off any Xenos that remain.
Game length is covered in the Special deployment and rules section
Deployment and terrain:
The scenario is played om the Standard 6x4 table. The tyranid player deploys in a 4x3 area on the short table edge. All terrain inside the Tyranid difficult terrain. All non-Tyranid infantry in this deployment must also take Dangerous Terrain test, to represent the jagged rock, molten stone and pools of acidic ichor left by the Bio-ship (Note: Monstrous Creatures and Walkers MUST take Dangerous Terrain test in this area. One slip one a boulder or a fall into an acid pit will harm even them. Tanks treat it as Difficult Terrain, their massive bulk and grinding treads crush over any small hazards like rocks, bone and the stray Ripper Swarm. Flyers and Skimmers treat it as open terrain, but Skimmers cannot end their movement phase inside the Tyranid deployment, as no pilot will risk leaving their ship on the ground in that area. The Guard player deploys anywhere else on the board. However, the Guardsmen deploy first, to represent their entrenchment around the crater, as well as receiving the first turn.

Scenario special deployment and rules:
"THE HORROR OUT OF SPACE": The Tyranid player does not deploy his whole army at first. Instead, he follows the following deployment chart (note, the Tyranid player MUST have two units of troops deployed by turn one:
Turn 1|He may deploy up to two(2) units of Troops and any number of Fast Attack units
Turn 2|He may deploy up to 2 more units of Troops, any number of Fast Attack and up to 2(two) units of Elites
Turn 3| He may deploy up to 2 more units of Troops, any number of Fast Attack, up to 2(two) units of Elites and one unit of Heavy Support
Turn 4| He may deploy up to 2 more units of Troops, any number of Fast Attack, up to 2(two) units of Elites up to 2(two) units of Heavy Support, as well as his HQ choice
"THE LEVIATHAN IS DYING": At the end of turn 4, roll a D6. on a 4+, the living ship lets out a massive death cry as its final massive organs die. All non-Tyranid infantry models take a Str2 hit, with no save allowed (that helmet won't stop your eardrums from bursting or your teeth shattering from the noise)
"FOR THE HOMELAND": Starting from turn 2, the Guard player may deploy his unit of Conscripts. They are treated in the same manner as units coming in form Reserve. At the end of each following turn, that Unit can be destroyed in its entirety to be re-deployed from the chosen table edge the following turn, during the beginning of the Guard's movement phase.
"THIS IS OUR LAND" All Guard units count as Stubborn and Relentless. However, a unit loses these rules if they break from an assault, or are reduced to 25% of the unit size at the beginning of that turn.
"ORBITAL BOMBARDMENT INCOMING"/"THE ENDLESS HUNGER": At the end of Turn 5, roll a D6. On a 5+ the game ends. At the end of Turn 6, roll a D6. On a 3+ the game ends. The game ends at the end of Turn 7 at the latest. If the Guardsmen met the victory conditions (See below) then it is considered that the hordes of vile Xenos have been delayed till a bombardment from a Imperial Navy ship bombs the Bio-ship and its deadly inhabitants to oblivion. If the Tyranid player meets the victory conditions, then it is considered that the Tyranids devour all the men before them, and spread throughout the countryside, claiming a foothold on the verdant, tasty world.

Victory Conditions:
HOLD THE LINE (Guard victory conditions):
Self explanatory, the Guardsmen must survive until the game ends. Even if a single Guard unit survives,it is considered a win. Fleeing and off table units do not contribute and are considered destroyed for all intents and purposes. If all of the Tyranid army are destroyed then the Guardsmen have won a crushing victory, and instantly win, no matter the turn.
THE DOOM OF THIS WORLD (Tyranid Victory Condition)
The Tyranids must annihilate every single unit in the Guard army in table to gain a victory (they are gonna need a lot of bio-mass to spearhead a planetary invasion.)

Comments, suggestions, criticisms are welcome and encouraged.