Two issues:

1. I have 28 Pro Tools licences to install on our computers. One per machine. I have created one iLok account and redeemed the licences in Avid Link.

It seems that every computer I try and launch Pro Tools asks me to sign in to iLok and boot off the previous computer, so that I can only have one licence open at one time. What should I be doing?

2. Also, one of the computers had the wrong date. When I changed the date (one day out) Avid Link refuses to let me open it. I've reinstalled Avid Link, but it won't have it.

Help required please! Thanks

I thought every Protools system needed it's own physical ilok connected via USB (some universities I work at use an internal USB port or loop a short USB extension to inside the case so irlt can be locked in. 

In case you have no pro tools version at home, you can of course buy an older interface intended for LE (pro tools 8 and earlier) for almost nothing. (Before PT9 you didn't need an ilok - just a pro tools interface.) As long as that interface is compatible with PT8, you can open PT9 and PT10 sessions. It might even work back to PT7, but I haven't tested that personally.

It would be nice to have all the neat new features, but since you're "younger" as you put it, if you don't have any version of the program at home, the best thing you can do is just get working with it. Even experience in an ancient PT environment like 5 is largely transferrable to the current version. If you're already experienced with the program, just ignore this.