I bolded and put italic on the important parts.Champions of Valor, page 6 wrote:Book of Exalted Deeds
addresses the concepts of
good and evil in the D&D universe. This chapter
examines those issues in the context of the FORGOTTEN REALMS
campaign setting, providing advice for DMs and
players who want more valor and heroics in their campaigns.
Good and Evil in Faerûn
Faerûn is an interesting place, to be sure, when viewed in terms
of good and evil. The goddess of magic is good, so all magic
ultimately comes from a good source, and while she can restrict
magical access to only good creatures, she does not do so or risk
upsetting the balance of power in the world. The god of the dead
is neutral, seeing death as an inevitable thing but not something
he wants to promote or encourage before its due time. Several
nongood deities allow paladins in their service, promoting only
the most lawful and good aspects of their faith. The god of
knowledge is neutral, while the gods of literature and song are
good. The protector of caravans is neutral, while the goddess of
festhalls is good. While the D&D game views good and evil in a
more black-and-white sense than what exists in the real world, it
is clear that in Faerûn, these concepts are not so cut-and-dried.
That said, we can use the godly portfolios to determine
there are some things in Faerûn that are definitely good or evil.
Nature, rather than being an indifferent or neutral force,
is often good (Chauntea, Eldath, and Mielikki are good, while
Silvanus is neutral) . Hereditary rule by qualified nobles is
associated with good-Cormyr is the only true human monarchy and
is considered a good nation; Mulhorand is ruled by lawful good
hereditary priest-kings; Evermeet and the Great Rift clans are
good monarchies. Light, whether sunlight or moonlight, is good
(Lathander, Selûne, Horus-Re, Eilistraee, and Sehanine Moonbow
are good deities of light, dawn, or the moon). Undeath, wanton
killing, and destruction are evil (Bhaal, Myrkul, Velsharoon,
Kiaransalee, Cyric, Talos, Set, and Malar). Oppression, conquest,
and inflicting suffering are evil (Bane, Loviatar, Lolth, Gruumsh,
Urdlen, Deep Duerra, and Talona), as are darkness and thievery
(Mask, Shar, and Vhaeraun).
When viewed in this way, the deities of the setting help define
the borders of Faerûnian morality. In short: Life, concern for
others, and respect for nature are good, while disruptions of the
natural cycle and abuse of power are evil. Thus it is quite possible
for a powerful good government to act in an evil manner by
abusing its power, destroying nearby lands, or engaging in war
for the sake of glory or territory.
Book of Exalted deeds can not be entirely applied to Forgotten Realms as seen from this quote, in fact picking BoED for things that can be applied is the way to use the book for Forgotten Realms.
As for the topic in general
Talona is the goddess of poison, and she is a Chaotic Evil deity. Ofcourse, things may not be that simple, but this is a basic guideline according to Champions of Valor. The use of poison to cripple someone is inflicting suffering, and inflicting suffering is evil in Forgotten Realms. The underlined part answers HOW nongood deities in FR allow paladins. Their paladins promote only the the most lawful and good aspects of their faith. If paladins alignment comes into conflict with their god's dogma somehow, the alignment comes first.