Also, thanks dr. steve for your response to my initial post on this subject. It does seem to me that if one accepts OSAS, one essentially must argue 'irresistable grace,' at least after the point of conversion, making them, as you say, "functional Calvinists" disagreeing only with when grace becomes irresistable. Further, it would seem if one argues that until conversion grace is resistable, then one cannot escape the notion that, in the main, our salvation rests on just how we choose to exercise our will, thus making our own salvation at least somewhat dependent on our "work." Is this logical?
As to the first point, the answer is 'yes,'it is given to all and I think, quite honestly, we must say that, depending on the definition of 'work,' but for the 'action' of the will of the believer, there would be no belief. Many years ago, I came up with a rather cumbersome analogy. Imagine a lever balanced upon a fulcrum or pivot point with very large weights (thousands of pounds on either end of the lever) and you are standing on the lever astride the fulcrum point such that, if you look straight ahead, the lever remains perfectly balanced, but if you look either way, the lever will tilt that way.
Now, if the lever tilts and you are asked what 'caused' the lever to tilt in that direction, would you say the great weight supplied at the end of the lever or the slightest additional weight of the 'look'? Certainly, in one sense, what overcame the great weight on the other end of the lever was the great weight placed on the end toward which you looked. On the other hand, it was the very slight, marginal weight caused by the slightest turn of your head which was the causative factor in the tilt.
I believe that is the sense in which the believer's decision of the will 'causes' the result of conversion. Certainly, one must admit that the causative decision of the will is the marginal determination of the conversion (or not), but it is the grace supplied by God which overcomes the great weight of sin on the end of the lever and allows the decision of the will to be influential.
Secondly, I think you are also correct on the 'eternal security' question. I personally think it is very difficult to argue that free will is decisive until conversion and then disappears thereafter. I have heard the argument that, once saved, the believer sees so clearly the benefits that he would never want to sin and therefore never be tempted to reverse his decision for Christ. This, it seems to me, negates much of the express purpose of Johannine writing ("I write this that you need not sin" -- clearly written to believers) and doesn't meet with our actual experience. Not only do we as believers continue to meet the very real thrusts of sin and temptation, but we see and have seen those around us, whose experience (so far as any other human can determine) is so much like our own that we must believe they were saved and had that testimony of salvation within their experience, and yet later made another decision to renounce Christ. [BTW, 'fell away' may be an accurate third-party description -- it is after all Scriptural -- but in our modern vernacular, it has too much of an 'accidental' ring to it. It takes a similar decision of the will to renounce Christ as it took to accept Him in the first instance. One no more 'falls' out of salvation in the accidental or negligent sense than one 'falls' into it.]
So, I think your logic is basically correct and one must decide for himself which theological view most closely comports with the totality of the Scripture and ones own observation of believers in the church universal.