Would going to the end with some stacks of blocks to setup a hideout/bridge to the main island before going in with all my diamond gear be a good idea? I’m worried about getting knocked into the void before getting onto the main island, or is this a non-factor?
You absolutely can fall or be thrown into the void when first arriving in the End.
Be aware that the only way to exit the End without first killing the Ender Dragon is to die, which returns you to your spawnpoint (i.e. last bed slept in, or World Spawn if no valid bed). You may wish to take an Ender Chest with you to stash important gear (it may get destroyed by the Ender Dragon but the contents are safe).
People have done it without armor or melee weapons, with a guitar hero controller, or even while playing as a fish. It’s nothing to be super afraid of.
Enchanted diamond armor, a good bow, 2 stacks food(to explore outer end afterwards), a couple golden apples, several stacks building blocks, a bucket of water, and you should be good to go.
If you really wanna go the extra mile, bring a good melee weapon, some regen/instaheal potions and some slowfalling potions, then you’re ultimately set. Good luck man. And as always, it’s important to know what you’re doing and not frantically run/jump around.