I do mostly mainstream/top 40 venues and the trick is selection and placement and good clean mixes between tracks. Try and program 20 to 30 minute sets of a similar vibe that constantly build in energy, then slam in something else and start again. This keeps the dance floor energy up, but also rotates your crowd to the bar – and if you want to impress the owners/managers, make them money!
Try and get a sense early just how mainstream this place is. If it is your typical top 40 bar/club, they aren’t going to respond well to you going effects nuts and cutting up their tracks – they want to sing along. For the actual mixes, try and line them up so that when song A hits its out, the main kick of song B hits – only leave long instrumental breaks if you are making announcements, or they are really, really interesting for some reason. If they are throwing their hands up constantly, you’re probably on the right track.
Not sure where you are located – but that’s the top 40 trick around here, and most of the places I’ve been to around North America… But most importantly, stay calm and enjoy yourself and you’ll do just fine. Good luck!
PS. Almost forgot, don’t let a ladder stop you from bringing what you need. A place I used to work at quite a few years ago had that kind of booth, and I’d just load my decks (it was the pre-digital days) into backpacks and have the doormen pass them up to me. Space in the booth is your limitation, don’t let access issues slow you down.