No, because one may pray on an elevated area only if it surrounded by walls; an exception is made for a synagogue attendant who prays on the Bima to make announcements or tend to other duties relevant to the prayer service (Mishna Berura 90:7).
One may pray in the ruins of a building if the following three conditions are met: 1) either the site is located in a field, or the individual is there with his wife; 2) the remains of the building are sturdy enough that there is no risk of it collapsing; 3) he is there with one other person or carrying a lantern (Mishna Berura 90:14).
Yes; since there is a wall in between him and the Aron, he is not considered as turning his back to the Aron. Nevertheless, when building a synagogue a congregation should preferably not construct auxiliary rooms behind the Aron. (Mishna Berura 90:21)
He should preferably pray at the time when the congregation prays; if, however, the congregation prays late in the morning, and he will thus be unable to eat or learn for several hours, he may pray earlier (Shulchan Aruch 90:9, Mishna Berura 90:31). If the congregation prays Arvit early, before sundown, he should nevertheless recite Arvit only after nightfall (Mishna Berura 90:32).
Yes (Shulchan Aruch 90:10). According to some authorities, if he has time to return home and pray the Amida before the final time, he should do so, rather than recite the Amida in the synagogue before the congregation (Mishna Berura 90:36).
He should preferably pray in the farther synagogue, so that he will earn more reward for the travel (Mishna Berura 90:37). According to some authorities, this does not apply to one who drives to the synagogue (Halacha Berura). Furthermore, if praying in the farther synagogue will cause one to lose time for Torah study, or if this requires passing through an area where he will see inappropriate dress and the like, he should preferably pray in the closer synagogue (Halacha Berura).
Although the Shulchan Aruch (90:13) allows spitting inside a synagogue, this ruling applied only in times when floors weren't tiled; nowadays, when synagogues have tiled floors, one may not spit in a synagogue (Halacha Berura).
A study hall used for public Torah study, like in a Yeshiva or Kollel, is always preferred over a synagogue as a suitable place for prayer; other study halls are preferred only for those who study there (Mishna Berura 90:55).
The Rama (90:18) writes that strictly speaking, those who spend all their time studying Torah, and break only for absolute necessities, may pray privately in their study halls rather than go to a Minyan. He adds, however, that they should not do so, as the laymen might follow their example and not attend the services in the synagogue.
Large, mobile objects, as opposed to small objects, and stationary furniture such as beds, chairs, tables and the like (Shulchan Aruch, Rama 90:21). The Mishna Berura (90:66) cites the Taz as adding that one need not avoid objects that are used as part of the prayer services, such as "Shtenders," even if they are large and stationary.
The Rama (90:24) allows praying in front of one's Rabbi in the synagogue, claiming that this is forbidden only when praying without a Minyan; Sepharadim, however, draw no distinction in this regard, and forbid praying in front of one's Rabbi even in the synagogue (Halacha Berura).
They may either wait for somebody to cover the urine, or move four Amot (6-8 feet) away from the urine or outside the synagogue altogether to complete the Amida (Shulchan Aruch 90:27); according to the Rama (90:27), it is preferable to leave the synagogue.