Fixes some runtimes [IDB IGNORE] (#17194)

* Fixes some runtimes

* typo

* No more infinite mannequins

* crash

* More runtime fixes and  pressure fling

Makes it so you can unwrench pipes that are pressurized, at the cost of being flung back from the pipe. Higher pressure = longer distance and faster.

* Fixes a memory leak and a bug

code/modules/mob/living/carbon/human/species/station/protean_vr/protean_blob.dm

@@ -197,10 +197,10 @@
 		humanform.species.update_misc_tabs(src)
 
 /mob/living/simple_mob/protean_blob/updatehealth()
+	if(!humanform)
+		CRASH("A protean blob does not have a humanform! src = [src] ckey = [ckey]")
 	if(humanform.nano_dead_check(src))
 		return
-	if(!humanform)
-		return ..()
 
 	//Set the max
 	maxHealth = humanform.getMaxHealth()*2 //HUMANS, and their 'double health', bleh.
@@ -324,6 +324,8 @@
 
 /mob/living/simple_mob/protean_blob/Life()
 	. = ..()
+	if(!humanform)
+		CRASH("A protean_blob calling Life() has no humanform! Src = [src] ckey = [ckey]")
 	if(!humanform.nano_dead_check(src))
 		if(. && istype(refactory) && humanform)
 			if(!healing && (human_brute || human_burn) && refactory.get_stored_material(MAT_STEEL) >= 100)
@@ -654,6 +656,8 @@
 	return ..()
 
 /mob/living/simple_mob/protean_blob/handle_mutations_and_radiation()
+	if(!humanform)
+		CRASH("A protean blob does not have a humanform! src = [src] ckey = [ckey]")
 	humanform.handle_mutations_and_radiation()
 
 /mob/living/simple_mob/protean_blob/update_icon()

code/modules/mob/living/simple_mob/subtypes/animal/giant_spider/tunneler.dm

@@ -155,6 +155,8 @@
 
 		// Update T.
 		T = get_step(src, get_dir(src, destination))
+		if(!T) //There is no turf in that direction.
+			return FALSE //Hit a non-existant turf.
 		if(T.check_density(ignore_mobs = TRUE))
 			to_chat(src, span_critical("You hit something really solid!"))
 			playsound(src, "punch", 75, 1)

code/modules/mob/new_player/new_player.dm

@@ -187,6 +187,7 @@
 			client.prefs.dress_preview_mob(mannequin)
 			var/mob/observer/dead/observer = new(mannequin)
 			observer.moveToNullspace() //Let's not stay in our doomed mannequin
+			qdel(mannequin) //We're not used anymore, so goodbye!
 
 			spawning = 1
 			if(client.media)