Yes it will be safe.The whole point of these compact fluorescent lamps is that the waste only a fraction of the energy as heat. The only reason for the restriction on the wattage of an incandescent lamp was fire risk from the heat generated. The new lamps will just get slightly warm.
As for the second part of your question, you won't be able to make the change without also changing your light fittings. I have replaced one third of the bulbs in my house but the remainder are just not suitable. We need much smaller compact replacements for many situations. I think the proposed two-year period for change is too short. It should be phased in with all new light fittings being sold having to be appropriate for CF lamps.