Please outline the fundamental Kalam and evaluate its weaknesses

The Kalam argument is a cosmological argument and is of a deductive nature - that is to say it is logically structured in such a way that if all the premises are true, then the conclusion must be true (ie it aims to be a valid argument). It reads, premise by premise, as follows: P1: Whatever begins to exist must have a cause P2: The universe began to exist C1: Therefore, the universe must have a cause. Attacks on this argument normally attempt to argue that there is no conclusive evidence the universe began to exist - whilst we may have scientific evidence which is indicative of a start point, there is no a priori reason the universe could not have existed forever, and as such P1 is wrong. In response to such a claim, defenders of this argument state that something can not come from nothing - everything must have a cause - for it defies everything we understand about physics to claim that things can merely spontaneously appear; this is reinforced further by empirical evidence, we have never witnessed something come from nothing in all of human history - all claims to the contrary have fallen apart under scientific scrutiny or were made in a time long before scientific thought and technology were widespread. However, this argument is a regress argument which seeks to hail God as the termination of that regress - if everything must have a cause, detractors argue, then so must God; if everything need not have a cause then the universe may well be infinitely old. Further still, this argument is then usually extended to assert that this first cause must have been some sort of Philosopher's God (an omniscient, omnipotent and omnibenevolent being) and yet the fundamental argument proves no such thing - even if all premises are held to be true, and the logical structure is maintained as valid, there is no reason this argument does not prove the existence of some other form of architect or algorithm which is not in anyway similar to a Philosopher's God.