Once again:
<b>(1)</b> Yes, people do have a right to say you're being reckless if you intentionally have a child knowing, in advance, that it'll come down with a (likely fatal) illness and (if not) something that will haunt them for as long as they live, adding an inordinate amount of issues to everything from employment prospects to personal relationships. 1/4 is worse odds than Russian Roulette with a 6-shooter, and I can hardly imagine anyone here defending playing <i>that</i> game with your offsprings' lives. Even if you merely pointed it at their leg, instead of their brain (and with CF, the latter is as probable as not).
<b>(2)</b> Yes, this would be as reckless if you did it with a 1/4 chance of childhood leukemia, Tay-Sachs, or any other highly dangerous and life-compromising illness. For other things that run in the family, such as a 1/3 chance of adult-onset breast cancer, there's obviously a sliding scale of black-to-grey (and make no mistake, there are grave responsibilities inherent in <i>any</i> decision to introduce more thinking, feeling humans into the world), but the ethical issues involved are considerably less serious. All adults will eventually succumb to illness of one sort or another, so unless it's a disproportionately high risk, almost every parent is on equal moral footing by default.
<b>(3)</b> You <i>can't</i> know if it's better for any particular person to be stuck with a disability. On the other hand... Judging from opinion polls, like "Would you appreciate cancer?" (which, as I recall, was something like 99% saying "No"), and the likely fact that, if you were offered a cure, you'd take it, the argument that it's as good to be ill as it is to be healthy is transparently false.
<b>(4)</b> No, this doesn't mean existing people with CF are worthless, can't enjoy their lives, blah blah. Just that recklessly endangering a future child's health, when you're aware of the risk--it doesn't just hit you out of the blue--and capable of averting it, is... reckless. By the way, the debating technique of bastardizing an opponent's position while ignoring his actual argument is known as the <a href="http://www.nizkor.org/features/fallacies/straw-man.html">strawman fallacy</a>.
<b>(5)</b> The belief that people are born with crippling disabilities to glorify invisible beings who, if they were as righteous described, would neither need nor want such "glory"--or worse, that it's a good thing to introduce more cripples into the world rather than healthy kids, because said beings would approve--utterly disgusts me. To make that--permanent and unchangeable--decision for your kids, who very well may not share your faith or appreciate their dying bodies bringing Jesus glory, appears sick on a number of nauseating levels.
<b>(6)</b> There are lots and lots of special-needs kids--including those with CF who've had their own parents die--who could stand to be adopted. If you really don't care about getting a kid with all that baggage, why not go for an existing one? (This obviously wouldn't apply to those parents who can't adopt, but it's something to think about.) Heck, why wouldn't God approve of that even more?
<b>(7)</b> Yes, I feel <i>very</i> strongly about this, and if I can ensure one <i>single</i> child is born without CF--without an automatic predisposition to unemployment, endless needles and PICC lines from childhood on, feeling the gurgling and drowning-like sensation of blood oozing in the lungs, eventual organ failure and transplant--because their parents came to their senses, and used IVF or adoption agencies instead of taking the risk (for example), I'll be very, very satisfied.