Dear RIOT and fellow summoners,
I believe that, instead of giving each beta tester some RP and IP, Riot should allow PBE testers to have access to all champions, runes, and rune pages (skins optional cuz they don't really affect game). I believe this because it will be very convenient for players to test the champions that are being tweaked in the beta patch. Also, runes and rune pages are very desirable in that they let you not only play a champion effectively, but allowing players to experiment with rune combinations could lead to the discovery of an issue or an exploit. Also, as a side note, having all unlocked content may draw more testers in.
TL;DR: All unlocked champs and runes would make testing be easier and more appealing