1. I mean it's a huge help, it will make sure you won't be throwing enemies too overpowered for a party to handle and they have a lot of neat ideas you'd never think of in terms of monsters and monster abilities. But I guess it's not strictly necessary. Do expect very easy or very hard fights until you trial and error your way onto what is a happy medium. And make sure your players understand this. On the flip side, don't be afraid to fudge a couple rolls, sneakily take off some total hit points or maybe give something a few more than you originally planned to make sure encounters go a little bit more smoothly.

2. I just steal my player's percentile dice whenever we don't have minis. Each of them have their own special set, so we know whose is whose. Or use lego minifigs, or coins, or really anything at all. I once played as the cat from a monopoly set and my friend was a connect 4 piece. The figures are probably the least necessary thing you need.

3. I'd say there is no trick and it's all up to feeling out what your players want out of the game. Generally speaking, what sort of tone do they want? Is it going to be casual a joking around, making quips and puns? Maybe they WANT to play a game where food and water are real resources to manage, and the challenge is a part of it. Sure you may feel resurrection is cheap, but players might not want to be someone else. Be flexible. Again, communicate communicate communicate. Don't force your players to count pennies and track weight limits if it just wouldn't be fun for them.

A good tip to help if you feel one person is very disengaged is to look over what skills their character picked. Players pick the skills that let them do what they want to do. The barbarian has taken points in swimming, climbing and jumping. Clearly he wants to be the guy being athletic and saving the day that way. Maybe have some rivers to ford, or cliffs to climb that let him really feel like a badass when he does it, and then throws the rope down to pull the others up. Or if your rogue has lots of "talking" skills and disguise, he wants situations where he has to sneak in, bluff information out of people, and be the hero that way. But don't overdo it. If you spend half an hour just chatting with only the rogue while the others just sort of stand around, you can bet someone is going to pull out a phone, simply because there is nothing for him to do. It's a fine juggling act, but you'll get better as time goes on. It's also fine if you do this and the player just isn't super interested in being the star of the show. Not everyone wants to be doing cool things all the time. Some people just wanna sit back, roll a couple dice when they're ready to brain some poor goblin and enjoy the atmosphere. If you find they're not terribly interested in being an active player, it's fine to let them do what they want to do, when they want to do it.

1. Your first time will likely be a shitshow. You're going to miss details you really wanted to mention, your players will probably end up murdering the npc that they were meant to get a quest from, and somehow a dragon burns down something. Don't mind it. The worst thing you can do to any player is to feel the reins slipping out of control and decide to start whipping them back on track. If your players mess around in town for the session and barely get on to slaying the goblin cave before time's up, it's to be expected. Nobody is going to be perfect, but it's only after you stick with it a ton of times that you're ever really going to feel like you know what you're doing.

Finally, there is a running theme many people seem to have issues with in DnD. You want to be open and communicative. If you're having issues figuring out what people want, talk to them. If someone is being annoying, talk to them. If your players have issues, make sure they know to talk to you. Talk, and if there's criticism of something you did, or how you did something, take it on board. That's the real secret to an epic DnD game.

Good luck!