As with any sort of change, there are risks involved. Jupiter is the planet of expansion and ruleship, and neither of these are necessarily safe things. There's a reason Jupiter is also associated with storms, with anger and lust and pettiness.
One risk I've identified is a tendency to try to control the expansion to much. "I want x, and it has to happen in this particular way." Well, it may be that the particular way you want it will not actually make x manifest. Working with Jupiter is a very organic process, and in my experience it works in fits and starts. Sometimes, you'll get frustrated with the pace, either too fast or too slow. Again, in my experience, meditation helps even out the fits and starts, and lets you see that a pause in expansion is a chance to consolidate, while a breakneck expansion can be managed with judicious application of the word 'no'.
Another risk is the avarice which comes along with expansion. The more you get, the more you want; the more you want, the more you get. It becomes a cycle of expansion for it's own sake, and the foundations can become unable to support all the expansion. The whole thing can collapse. To manage this, one should speak with Saturn (who works with limitations) and make sure there are both limits on speed and manner of expansion, as well the Solar energies for balance and generosity*.
One can lose one's starting vision, and get lost in the labyrinth of opportunities that present themselves to the practitioner. It's a good idea to review your starting goals, and make sure a) that they're still the goals you need to enact, b) that you haven't achieved them, and c) that you're still working towards them.
It is my feeling that the risks are easily managed. Go forth, and do likewise.
*I say the Sun for generosity, as the solar orb gives all it's energy freely for all life to take and use as best it can.