Sounds to me like you need to find a new IT guy that understands web servers. NoF still works as well as it did 2 years ago unless your web strategic needs have changed. There is no other software that manages web sites the way NoF does. And if you know Bootstrap or Foundation, it's not hard to take a NoF web page and make it responsive if you really need to.

Bottom line - you won't find another application that offers site wide management the way NoF does and that also offers automatic responsive output. All the responsive frameworks and the applications that are based on them offer a page by page approach, not a site wide approach. That means you can't change something in a MasterBorder and have it flow through the site automatically. You have to make the same change on every page.

You pays your money; you takes your choice. Easy site management or easy(er) responsive output. You can't have both, not at the moment.

As to whether or not NoF is working on another version will only be revealed when and if they release that other version. The current management has never signalled its intentions ahead of time. However, Team Netobjects is alive and well and developing Koken, their other application. My guess - and I have no knowledge to base this on - is that we will see an integration of Koken and Netobjects at some stage in the future. And that will, once again, be a killer app.