[tomb1]

Willkommen Manu. Ihr Englisch ist sehr gut, besser als mein Deutscher.

If you have only one table but have 30 players, most of the people in the room will have nothing to do while only a few are playing. That could be very boring to them. I would not like to stand around for 4-5 hours waiting for the final table. I would suggest you use temporary tables or something else so you can get all 30 players playing at the same time.

But that would mean you need more chips for 30 people simultaneously.

And if you are going to have multiple rebuys with new players, you could expect many rebuys so you probably need more chips for this also. You might consider no rebuys -- they can be fun but they definitely make the tournament much longer.

With a T€1000 starting stack, if you provide 20/16/5 chips that makes you buy more chips than you need. If you changed to having fewer of the €5 chips and more of the €25s, you would use the smaller chips just for blinds and small bets, and the €25s would be used for most of the betting. You might consider this starting stack:
5 x €5
15 x €25
6 x €100
Total 26 chips per player. You would only need <300 chips for each 10 players (50/160/60/20), but many more for rebuys.

When you get to the final table, you should let each player take all his chips with him. That means you need enough chips for at least T€30.000 (and maybe a lot more for rebuys) on the table at the same time, This is where you would need your €500 and €1000 chips. And you should start with a higher blind structure at the final table.

Just some of my thoughts, my zwei pfennigs worth.