Reservation / invoice solution recommendation please?

Hi all,

Do you have any self-hosted recommendation or software application in the cloud / CRM that my client is looking for?

1: we want to add a quote button with template options for the organization to include information to quote
2 – Xero and the portal (WordPress and add-ons) do not communicate with each other, so the invoice was canceled. Not just a few but a lot. I was told that this can not be fixed unless we add a new user to the portal, but we do not know who the user is as there are many! So, is it a possibility that Xero can respond with multiple options to correct the errors? They gave us unclear instructions
3: Is it possible to create a bulk reservation on the portal for an organization to make a multiple reservation at one time (add more Botton reservation?) And have it all in one invoice instead of 10 invoices?
4: the subcontractor is not an employed teacher; you want to create a manual space where we can put the name of the lecturer: email address in the portal and only send the work assignment (without having access to the portal). The subcontractor only works for us maybe 1-2 times that. They told us that we had to create a portal user, but that takes a long time and is not worth it for a teacher who only works once or twice.
5: is it possible to have 5 users with payments divided into a single reservation, instead of me making a SAME reservation for each user? Makes sense?
6 – At some point when they have events for 3 days or so, at some point the customers divide the payment of their funds to cover the cost … We had to go through the difficult path trying to solve this.

Thank you