Oh I agree. I highly doubt she's leading youth to Satan. That's so blasé these days; something kids' parents did.
While I agree the occult symbolism is blatant, I disagree with the conclusions drawn by that blog. There is a great deal more to occult religions and spiritual practices than the blogger understands.
As far as the Bad Romance video is concerned, I see it as a continuation of a theme she's presenting on the dual nature of fame. I don't see the isolation chamber labeled, Monster, as anti-Christian in the least. The symbol on it is more a sword than a cross. The sword, in occult symbolism, represents mental power. It is reason and, therefore, control. Western occult tradition uses the sword in ritual ceremonies as a representation of the power of the mind to cut through what is occult (literally hidden), to discover the truth of revelation. It is the power of our mental faculties, those of reason, which allow us to control occult forces.
The bat is a dual symbol. It does have a connection with vampires and evil but its much older association is that of resurrection. Bats live in caves (vaginas), emerge at night (born in the death of night), return at day (die temporarily), and emerge again (resurrection) to feed. They are, in pagan and other cultures, symbols of good fortune.
The bath and the drink of vodka seem to me to be symbols of rebirth. At first resisting, then submitting, Lady Gaga is transformed into the fame whore but, in fact, she is not completely transformed. The burning bed and the immolation of the john show that Gaga is in control of her faculties. Her john burns while she remains untouched by the flames she apparently generated. Fire is a very ancient symbol of purification; one used by various religions to purify and, in the case of Catholicism, to allegedly purify heretics by burning them alive.
Whether or not the trophies represent the Devil or not, I don't know but it is possible. Note that in western esoterica, the Devil is not Satan. Baphomet is not Satan (despite what that blogger says). Instead, in western esoterica, the Devil represents our vices and self-destructive tendencies. There is no external deity or angel or anything else. There are just our inner demons which we construct and are slave to at our own will. If the Devil has hold over us, it's because we allow it to do so. What can destroy the Devil? The sword. The strength of our own mind, our own character, is what can defeat and destroy the Devil (or Devils) within us. We slay our own Devils with our own swords once we discover we have the means and the strength to do so. Our enslavement is, in western occult practice, entirely of our own free will. It seems to me that Lady Gaga is saying that she chooses this particular Devil, very aware that she is voluntary enslaved to it. She also seems to say that her self-awareness allows her to control the fame Devil (or as she says, monster).