With only a Pelangi installed there's almost no ice you can't safely facecheck - ok, you might lose the Pelangi, or take a couple of net damage, but you still forced the corp to spend good money doing that, and they probably didn't even stop you getting into the server.
There are a lot of programs here to juggle with only the 6MU total with Keiko but it's definitely doable. Start by using Botulus and Pelangi to safely pass early ice. Bounce them with Simulchips to maxmise their value. Install Leeches to gain extra value from those runs. Only install your breakers once your virus options start to run out. Save Stargate for when you can use it best - throwing it into the heap so that you can chip it cheaply into play is totally fine.