i would like to know flat out the effects of a weaker arrow to a stiffer arrow, and if arrow point weight will affect that

Will tip weight affect stiffness?  It'll affect the dynamic stiffness.

The heavier the point the weaker spine your arrow will become.

how will this affect the arrow in flight

Typically....your nock will kick right with a shaft that is too stiff.  Opposite if it's too weak.  

This is assuming you're RH.

yes i am and what is dynamic stiffness

If your arrow kicks right when shot out of a right handed bow that indicates your arrow is too stiff for your bow.  If you had say..a 145 grain tip to begin with and then put on a say... 200 grain tip then your arrow will weaken and either kick LESS to the right or fly more straight.  
When I tune my arrows I know that I want to end up using a heavy tip (280-300 grains).  So I use an arrow that will be stiff (kick right) with a 145-175 grain tip.  When I put on the heavy tip it weakens the arrow back to center and flys straight.

ok that makes alot more sense now thank you for the info

arch:

Static spine is what we test when we use a spine checker.  Tip weight won't affect this reading.

Dynamic spine is how your arrow reacts due to several factors (arrow length; tip weight; DW) when shot.

Adding feathers to your shaft will also make your shafts react more stiff.  I try to get a slightly weak reading when bare shafting, knowing the feathers will stiffen them, slightly.

GMMAT, you sure you got that the right way around?  Weak shaft = nock left, stiff shaft = nock right, for a right handed shooter.

If your arrow is too stiff in spine and you are shooting right handed, your arrow will come out of the bow with the nock end too far to the right. This will cause a fletched arrow to fish tail as it tries to straighten itself. One way to correct this is increase the weight of your field point.

If your arrow is too weak in spine and you are a right hand shooter, the arrow will leave the rest nock left. Again your arrow will fish tail and fly poorly as it tries to correct or straighten itself in flight. You can correct this by decreasing the arrow point weight or shortening the shaft.

If you are shooting left handed the reverse will take place. Too stiff-nock left; too weak-nock right.  

Determining correct arrow spine with a fletched shaft can be difficult. The arrow may be quicker than the eye and you can't determine nock left from nock right.  Find an article on bare shaft tuning. There may be a good one in the Shooters Forum on this site.

If you are new to shooting and still working on your form, bare shaft tuning can be frustrating. Each time you change you form, even in the slightest way, the bare shaft will react differently. Nail down your form first so each release is the same. Makes tuning much less frustrating. Good Luck.

Sam, the importance of shooting the correct arrow really becomes apparrant when shooting broadheads, because any spine problems are magnified greatly with a broadhead arrow.
look up A & H archery's website a sponser here, and look up the bow tuning section.
http://www.acsbows.com/