The re-valve helps tremendously with or without spring changes , but as stated if the sag numbers AND the ride are not plush then usually (especially when it gets better when you stiffen the clickers) , shows that the spring rate needs to be stiffer , the bottoming is fine if it only did it 1 or 2 times on the ride , the oil level helps with bottoming resistance , as does the Mid-Valve in the valving (Mid-Valve is the stack/piston on the Rebound Rod that sticks out of the Cartridge) , its the part that goes IN the cartridge
For sag , you should have about 55-65mm free sag on the forks for off-road , and about 45-55mm for MX (about 2.1 in. - 2.5 in. for off-road) , which shows your spring is too soft as you have way too much free sag , although keep in mind if your rear sag is off or your linkage is binding , it will haver a effect on fork sag , so make sure you have the rear squared away before worrying about the forks , remember .... balance .... front to rear is what makes a bike ride good
The Pressure springs can be had at Race Tech or Factory Connection , or buy them from Ken , he has them here as well , the Pressure springs will help with initial harshness , stock would be about 1.8 or 1.9 i believe on the 250 , and its 1.9 or 2.0 on the 450's if i remember correctly , though it could be less on the 250 , you might want to research that with Race Tech or someone (Ken should know) , as the rate does vary from year to year , so i am not going to say my figures are 100% accurate , i run a 1.76 on both my bikes
I would not say going to a 0.49 would have a "huge" difference , but even 1 rate should be noticeable , just as 2 clicks on the clickers is noticeable
If your riding smooth trails and using the majority of the stroke , then i would say your spring is too soft as is , unless you are really plowing the log face , but even that should not use that much stroke , it IS OK , to use all but even just 2 inches of stroke , as long as your not doing it all the time , in other words the bike should not be riding in the last half of the stroke the majority of the time , it should be in the upper 1/2 of the stroke most of the time , especially on flatter terrain , then it should be in the upper 1/4 of the stroke
Hope that helped explain it some ..