Hi, let me try and explain things to the best of my knowledge:

1. Mind if i ask whats your VPN? im asking because most seedboxes use OpenVPN or NordVPN. if you have any seedbox provider in mind, you can try contacting them and ask if they allow connections from your specific VPN, if not, you can always trust the VPN service provided in most seedbox offers and use them instead.

2. Yes, some trackers have issues with VPN which is why it is better to use the VPN service provided by the seedbox as it is mostly accepted on many private tracker.

3. Private trackers are able to track your ratio via the unique account passkey that you use when you download a torrent file on their tracker. This passkey is unique and very specific to each user registered on the tracker. You also need this passkey when you configure youre seedbox to automatically download torrents that are announced in the trackers's IRC channel.

4. Are you getting a dedicated server? well, it depends on the service you will buy/rent. There is a service called dedicated box/server in which you are the only user for that server and you also have a dedicated bandwidth to your server. There is also a service called shared box/server in which as the name implies, you are sharing the server with different users. In this setup, you are sharing everything, from the hardware resources up to the bandwidth connection. Of course, dedicated server/box is more expensive than the shared one.

5. As per the seedbox suggestions, from personal experience, you can check seedhost.eu for their services. They have a seedbox for as low as 5 euros and they have good speeds and excellent technical support. Most hardcore users here in TI uses seedboxes.cc as their provider, from their personal review of this provider, you can also be sure that the service is good. And check the seedbox reviews forum so you can have an idea of what to look for.