Okay, I’m just going to break it all down.
Any SP you get from daily rewards, recruitment bonuses, or DLC’s (boo) will first go to the redeeming queue. Depending on it’s source, it may or may not have an expiration date. Any SP sitting here will not count towards your total SP, and will therefore not impact alpha training to the 5 mil SP cap or injector penalties. Thus, it can be useful to leave SP here until you are ready. For example, I created several alpha accounts a while back, but saved every scrap of bonus SP I got. I trained the characters all the way to the 5mil SP limit, and then redeemed all that SP, which instantly bumped me up to about 6.5 mil sp on all those characters. And in case you’re wondering, I was able to hit the SP cap before any of that SP expired with about 2 weeks to spare. I used +3 implants, a 27 Perception/21 Intelligence remap, the 35 day/+3 newbro accelerator, and probably didn’t let their skill queues idle for more than 48-72 hours total over the course of their approximate 6month training time. Do note that the 35day/+3 accelerator only gives about 4 days worth of SP to an alpha, I didn’t do any skilling sprees on these toons, and the 27Per/21Int remap is a general remap, and not the most efficient remap. So even if you don’t use the accelerators due to their rising costs (I don’t think that they are available any more), you should still be able to hit the 5mil SP cap before any SP expires as long as you do a little planning.
Do note that there is no restriction to redeeming SP based upon account status or SP total. The only factor that matters is that you must make sure to redeem SP before it expires (login SP rewards typically have a 6 month expiration, while recruitment and DLC SP does not).
Once SP has been redeemed, it becomes unallocated SP sitting at the bottom of your character sheet. This SP DOES count towards your SP total, which will affect injector penalties and brings you closer to the 5mil SP alpha limit. Redeemed SP is not lost under any circumstances. Thus, if you have 4.5mil SP and redeem the 1mil SP recruitment bonus, you will then have 5.5mil SP total. However, since your are now over the 5mil SP limit, passive training will stop, and you’ll have to go omega in order to resume it. Because of this, it can be beneficial to delay redeeming SP until you have passively trained up to the 5mil SP limit. Whether this is the right decision for you depends on your particular circumstances. If you plan on playing as an alpha for as long as possible, or want to train as much SP for as little time/effort/money as possible, I recommend delaying redeeming SP.
Finally, you can apply your unallocated SP to skills. If your account is an alpha, you won’t be able to apply SP to Omega only skills. However, if save up a bunch of unallocated SP and then go omega, you can then apply all that SP to omega skills without restriction. Thus, it can be beneficial to save unallocated SP until you go omega. If your account then lapses back to alpha status, you won’t lose that SP, you just won’t get the benefit of those skills until you go omega again.
Okay, I think thats all the relevant information.
Advanced Skillpoint and Training Guide series Trailer for those who still want more information.