I'm curious on how Buddhist Sacred Texts are used in teachings and in practice [...] what authority do practicing monks and the Sangha give to the sacred texts? How are these texts used? Are they used merely as a guidebook or as intensely analyzed, as say, the Christian Bible?
In general, I think it really depends on the sangha and school. For example, in Sōtō Zen, probably the most read sutra is the Heart Suttra and Dōgen Zengi texts are frequently used. Texts are used by monks in the context of practice and any analysis that sidetracks from this purpose or shows signs of intellectual exercise, even slightly, might be explicitly discouraged (e.g. left to academics).
Monks, in Zen, don't seem very inclined to scholasticism. Also, they don't seem to easily fall in the trap of mixing the value of texts and attachment to it -- as attaching to written words is famously made fun of.
Yet, scholastic work was not only common but prominent in many eras and many traditions. During the early sects, different abhidhamma systems developed and were used as platform for discussing doctrinal points and divergences (even treatises on how to develop formal proofs were elaborated). Also, monks started writing exegesis.
Theravada inherited this tradition. In general, I think its monks, versed not only in the nikayas but in abhidhamma and exegetical literature would not hesitate to scrutinize any doctrinal text and analyze them in their minutia. In many lineages, abhidhamma has a distinguished role, though commentaries often receive surprising authoritative status. For example, some monks see buddhism strictly through the eyes of Buddhagosa.
Another example, Ledi Sayadaw caused great turmoil for writing numerous corrections to a commentarial book -- this reaction certainly smell a little dogmatic and not showing much of the skills of the Buddha's recommendation to the Kalamas. Also, it seems Ledi was a champion in turning abhidhamma as a guide for meditation.
Suttas are also not only restricted to be quoted in dhamma talks. They are chanted, memorized and studied by monks and lay people and they practice meditation following what has been taught in them.