You've asked three questions. I'll take them in reverse order.
Re "book learing" -- I read for 15 years or more before I bought Billy Ruff'n. You can learn a lot from "standing on the shoulders of giants". Reading will only take you so far, but it can help you prepare for passagemaking and heavy wx sailing. For example -- keeping a list of things experienced sailors do to prepare and the lessons they learned from mistakes will help you develop a "Hvy Wx To Do List" for your own boat. Procedural things, like hanking on the storm trys'l well in advance of a storm's arrival, and marina/mooring projects like designing and fabricating the means of securing your batteries, lockers and floor boards in case of a roll-over. Reading helps prevent being in a situation where "you don't know what you don't know". It can't tell you how to handle every situation, but it can help you envision what might happen on passage in a storm. From there you can start the process of preparing for it.
Re gaining "passage making experience" -- I started by crewing on OPBs (other people's boats). Once you have your own boat you do overnights and then longer passages of 2-3 days. If you learn to safely do a three day passage there's no reason to think you can't do a much longer one. A ten or even twenty day passage is in many ways just a series of overnights except you need to carry more provisions, ration your crew's energy, fix things when they break vs when you get to port, and generally have your head more out into the future -- thinking about / planning over a time horizon that you know will get you to safe harbor. The longest passage I did on OPBs was 7 days. The Hilo to BC trip you mentioned is probably twice that, but crewing on something like that will definitely help you prepare for your first offshore trip as skipper.
Re preparing for heavy weather -- there are two types of preparation that need to be considered: preparing the "physcial" stuff -- the boat, gear etc, and "psychological" preparation of skipper and crew.
As I mentioned above you can learn a lot about preparing the boat from reading, and undertaking projects on the boat that get the boat ready for heavy weather long before it's experienced. Things like those mentioned above, keeping your rig
and gear in top condition are good places to start. Things like rigging
your storm sails and sailing with them in moderate conditions, learning to heave-to, practicing deploying your storm drogue / para-anchor, etc. -- all these things help you prepare the boat and yourself before any 'trial by fire'. While much of this type of pre-work and practice can be done in moderate conditions, I think it really helps to have actually sailed your boat in strong winds (gale force) because that's the only way you learn how the boat and gear behaves when it's under real stress. I don't advocate going out in a gale to learn how to sail in one. But if you haven't gotten the experience in other ways, forcing yourself out on a day when it's really snotty may be the only way to get the experience you seek.
I think psychological preparation for heavy weather offshore is equally important. I find that the one of the hardest parts of sailing offshore in bad conditions is knowing that it's going to last for a while and that it may get worse before it gets better. It's knowing that it's bad and you really can't control things -- you can't make it better and that you can't make it go away -- that's what can really wear you (and your crew) down. Fear is your worst enemy and at times seems to be your constant companion. How do you prepare for that?
Training helps a lot. Confidence in the boat and crew are also important, but there's probably no real substitute for doing it. The first and only time I've experienced 60-70 kts at sea was on a really big ship. The worst storm I've experienced in my boat was a 3-day, 40-50 kt gale in mid Atlantic. Neither was any fun.
First priority is always to avoid bad weather. I've avoided many more gales than I've sailed through. The rules are simple:
1.) be in he right place at the right time (i.e. stay out of the hurricane box in hurricane season);
2.) pick a favorable weather window for departing on passage. Don't be in a hurry to leave;
3.) when you're at sea and there's bad weather ahead of you, change course to avoid the worse of it, slow down or stop (heave-to) to let it pass.
If you're at sea and bad weather is going to overtake you (i.e. you can't avoid it) -- make sure you do everything you can long before it arrives. I tend to over-prepare --I'll put in one more reef than is likely to be needed 6-12 hours before I expect the wind to get strong and I'll leave it in 12 or more hours longer than is needed. If it's forecast to blow 35-40 knots from abaft the beam I'll take the main down completely and run on a reefed jib
or stays'l alone. The boat slows down the motion is less violent -- the crew can get better rest... stress on boat and people is less. Storms at sea will usually go away faster if you are going slower.
To conclude a long winded post -- Reading helps, sailing offshore with experienced people helps a lot more, but in the end -- you just have to do it. If you sail a lot you'll end up sailing in bad conditions. Hopefully, you have a few 30-40 knot experiences before you have a 50 kt experience. Don't let the fear of the 50 knot experience keep you at the dock. When (if) you find the 50 kt gale, remember two things (things I told my wife when we found ours): 1. boats float if you keep the water out and that's easier when you batten down and slow down; 2. storms go away eventually -- never lose hope that 'this too, shall pass'!