Talking about deals you’ve worked on

Could use some advice as I’ve got an interview next week. During my time in banking (at two firms), I’ve closed 1 deal at my first firm (1.5yrs ago), and 1 at my current firm. At my current firm, I was staffed on the deal I closed during the diligence phase, so I didn’t build the model and was primarily just facilitating diligence. The other 3 deals I’ve worked on at my current firm either died (got really far in 1 process but was put on pause), or is close to signing (but was not a typical process so don’t want to talk about it). I know the most about the deal that was paused because I worked on it the most, is it okay to use that deal? Because then I couldn’t really speak to the transaction structure etc.

TLDR: is it okay to talk about a deal that ultimately died after LOI when they ask to walk them through one of my deals? Additionally, when they ask me if it would be a good investment, is it bad to say that i think they need to better improve their business model before I’d consider investing?