It sounds like you want the data about what Active projects each Staff member is on to be a field in the Staff table so you can create a filter/view based on it. To get that info you’d need to add a Lookup field to the Staff table so you can do a fie...

Create a new View in your Clients table that filters for only records that have Status == “Account”. Then in your Marketing Spend list table you can modify the “Linked to another record” field to be limited to only your new View in the Clients table...

I believe what you’re describing is literally a many-to-many Joint Table. Your “Option” table is adding calculated details about the combinations of Caterer + Venue that exist. Only relatively recently a Script was added to the Apps that allows you ...

I wholeheartedly agree that better support for joining is needed, but from the brief description of your use case it doesn’t sound strictly necessary. One of the key things to keep in mind is that in AirTable, unlike databases, calculations on data s...