For me I found that my Pure DoS Paladin was able to find utility in all but GMoF (this was tough but I think a Monk splash would find this one easier) ...
Paladin's have SP naturally - means a lot of abilities are on the table for use
Paladin's have martial skills meaning every melee ability is on the table. For Defensive stance Paladin's FoTW can be challenging to fully utilize but with imagination it can be effective.
Through EDs is the only way to be a Paly/Bard. There are some nice boosts in power around Tier 3 and Tier 4, including weapon damage increases through procs.
Draconic also has a few nice abilities, I like the Roar Fear Effect as it gives that Paladin Rally Feel. Also has the energy sheath ability and while there is UMD in paladin builds that at best will give you Fire and Ice, many of the higher quests have a lot of lightning, which coupled with Paladin Saves could mean the difference between taking 1/4 damage vs 1/2 damage - Sometimes having that reduced further by resist means taking nearly 0 damage instead of 100s. It is also a Tier 1 ability so you can twist it as soon as your move to the next ED.
Personally I would recommend the following minimum before you TR
Take DI to 3 720,000 XP
Take FS to 4 1,080,000 XP
Take SD to 3 720,000 XP
Take LD to 4 1,080,000 XP
Total of 3,600,000 XP - Or 600,000 XP more than 20 to 25. If you have the stomach for it go Tier 4 in GMoF. Once you've done that you will have unlocked the ability to go to all spheres, you are still limited to the gateway EDs on Divine and Primal but it will be easier to finish it up.
Personally I've tried different techniques of ED leveling from Doing the Minimum needed to move around (3 and 4 for gateways) and even the Max it (ie Tier 5 and maybe some more) before I move on.
Each has it's advantage and drawbacks.
Minimum leveling opens up EDs faster and helps gather Fatepoints and lower tier abilities for twisting - However at the cost of not having some of the more powerful ED abilities
Maximum leveling gets you to the more powerful abilities sooner but does not have access to the Fatepoints or other ED abilities as quickly.
Currently if just earning the XP from 20 to 25 (3,000,000 XP) is equivalent to:
2 EDs to Tier 5 or 3 1/3 Fatepoints
Approx. 3 Tier 3 and 1 Tier 4 ED or 4 1/3 Fatepoints