Other than confusing the living daylights out of your cost basis, I see little point in trading Apple on a periodic basis.
If you try to track the cap gains for tax purposes yourself, you are correct. It becomes an accounting nightmare. I do it with 25 stocks and I'm no accountant. The trick is that the brokerage house like TD Ameritrade that I use does all the work for you. Plus, if you use TurboTax, and get the premium version you can have Ameritrade populate your return with all the data in a few seconds for the whole year. This has been possible for at least the 4 years I've been doing it.
As I stated, trading around a core position has the advantage of doing better than simple buy in and let it ride growth, but it requires work. If you don't care to work at it your plan is best suited for you. I need to generate growth at a time ( in my mid 60's) when most are afraid to and just want to stay conservative. I don't work for an employer or a client anymore so I have the time to work at this like a daily job. Therefore I expect to earn what would be a normal weekly paycheck at minimum. The problem with stocks that don't pay a dividend, is you must sell in order to generate income. Trading at proper times is the only way to do that but to also grow your nest egg you must also maintain a position, The strategy allows for a happy balance between the two.
Only time will tell whether Apple can sustain it but periodic adjustments are as likely to happen.
Yes, time will tell and I can almost guarantee you that someday, even Apple will fall to flatline growth. Maybe it will also suffer the fate of RIMM or AOL etc. Maybe just huge but no luster like Microsoft. The trick is to be in during the growth period, not wait on the sidelines for a time when you can look back on history and repeat that age old bit of hindsight wisdom- "I coulda, I shouda." Better to say, "I did."
I have a relative who sold his Apple stock 3 years ago and got into Red Hat when it was at $26. This is another one that is flying high. I'm also interested in Priceline.com and started a small position at the beginning of the year. While Facebook is going to be the story of 2012, I'm afraid the IPO is out of reach but I will be watching and looking for a different story than the other IPO's that fizzled recently.