In no particular order.
If the boat is in the water, do not remove the mast. The motion mastless is HORRIBLE.
Notice of a storm. This varies wildly. We were anchored in Grenada, the Carenage, when we heard that a hurricane was almost there. Good thing it was a protected anchorage, because all we could do was secure our anchors and insure that chafe protection was in place. We were at a dock in Beaufort, NC when, very late in the afternoon, a hurricane formed off the coast of SC just a few hours from us. We couldn't leave because we had no way to go inland - drawbridges are not opened when a hurricane is bearing down - to guarantee the drawbridge won't get stuck open, and to allow as many people to drive away as possible. That one, fortunately, was a Category 1, lots of rain but no severe wind gusts. We were very, very lucky that the storm hit at low tide. Storm surge + high tide would have been very difficult.
Most places in the US one has plenty of notice, since the lows that form the core of a tropical cyclone usually form off the west coast of Africa. or in the center of the Caribbean.
What one finds is that the storm, long before it reaches land, has sucked all the wind out of an area, making it even more difficult to try to run away from the storm. The other issue is the storm surge - some places in the Caribbean there was extremely destructive storm surge-driven waves and swells, but nary a breath of wind. Storm surge plus monster winds is a scary situation, which is one reason that a place like Simpson Bay Lagoon in St. Martin was long considered the perfect hurricane hole. (Hurricane LUIS in 1995 demonstrated that a bad enough hurricane put the lie to "perfect hurricane hole", as had Hurricane HUGO did in 1989). Read about some of the nastiest hurricanes of the Atlantic basin HERE
Yes, absolutely take off EVERYTHING on deck. Remove Biminis, sails, tape down instrument covers, secure all sheets and lines. Anything that can fail will during the high winds. Before our first hurricane, in 1985, we went out to the mooring that our boat was on and secured the mooring with a second mooring line, just in case the original line broke. It did, and the new line held. Whew! Anyway, we stripped everything off the boat, removing all the sails, etc. Almost all the boats at that marina were hauled out - the owner and his crew working through the night to get them all in. The hurricane hit the next day, and we went down to the boat a day or so later to see how she had fared. This after seeing all the boats driven off their anchors or moorings in into the marsh where the receding waters left them, high and dry. Watermelon survived very well, but looking her over, we realized that we had overlooked the binnacle cover, which was blown away by the hurricane.
I assume that when you say "slipping" the anchor, you mean what I call "dragging" anchor. In other words, the anchor has lost purchse and the boat is adrift with its anchor down. Did you read one of the threads on this forum about anchoring, and dragging anchor? Even in moderate conditions there's usually one or two boats that drag anchor in an anchorage, even when they have been very careful. And of course the careless and clueless drag anchor even more often. Lots of reasons for dragging anchor. Another boat drags anchor and slams into your boat. The winds are so high and the seas so rough that the shock loads on the nylon rode cause it to fail catastrophically. The bouncing of the boat in the wind and storms dislodges the anchor - perhaps the bottom is rocky, hard mud, thin sand over rock or coral, etc., etc.
After sitting out a week of high winds in the mangrove swamps of the Everglades this past winter, I can understand why many cruisers swear by tying up in the mangroves. The density of the foliage slows the wind, and the dense root system dampens the seas. We couldn't go into the passes in the dinghy because the wind was howling, yet where we were anchored there was just a pleasant breeze.
Wow, I do go on. Sorry, time for you to catch your breath.
Oh. In the new Coles' Heavy Weather Sailing, is Warren Brown's sailing through a hurricane recounted? It was memorable for his dinghy, secured on the foredeck, getting loose. Some sensible tactics used by him - I hope it remained in this new edition. I swore by this book. I think I'll have to find the new edition to see how much the tactics and advice have changed.