Holding cash is expensive. The market can run away from you and never come back. Perhaps a better strategy would be to hedge your investments with options, etc. so that if a rainy day comes, you can deploy your protected assets where they will do the most good based on where you and the economy are (stocks, real estate, traffickers and fake documents, who knows?).
Even with money available, you'll be caught flat-footed as a house flipper if you don't have an intuitive grasp of the amount of time and money required for various remodeling tasks, or if you lack general construction knowledge (quick, what gauge wiring must be used for an electric stove!? When is PVC pipe acceptable as an exhaust vent!?). Develop this knowledge first, by reading books, researching building codes, and doing your own hands-on work. Bonus: you might find you don't fancy this kind of life at all.