Extremely Partial Answer
Number five
A side spin in pool or a man from Ross-on-Wye,
ENGLISH
with rocket or mad; someone from TSRI,
SCIENTIST
the father of Jacob or writer of scifi.
ISAAC
So this refers to
NEWTON.
The flakes that keep floating around in the cold air,
SNOW
the colour of what you find just outside Dover,
WHITE (as in White Cliffs of Dover, thanks @Stidgeon
a melon, banana or lime or d'Anjou pear.
FRUIT
This refers to
SNOW WHITE FRUIT: so APPLE (thanks, @Stidgeon!)
With murder, extinction; a Catholic sermon,
MASS
a luminous square in the birthplace of Merman,
FORCE?
increase in velocity can be determined.
ACCELERATION
This refers to
NEWTON’S SECOND LAW
Altogether...
??
Number four The Pianist and Chinatown director's first name,
ROMAN
with Weimar or people's; most countries this form claim,
REPUBLIC
some twelve of these were understood by John Paul's brain.
APOSTLES?
This refers to
SAINT PETER?
"What's up", a term used by a Bunny quite snidey,
BUGS
profession of J. Jonah Jameson in Spidey,
EDITOR
creator of Windows, IT house now mighty.
BILL? GATES?
This refers to
A stingy thing followed by golf exclamation,
Bee+fore = BEFORE
the dominant degree in chordal progression,
FIFTH
between Mike and Oscar in NATO's expression.
NOVEMBER
This refers to
GUY FAWKES
Altogether:
??
Number three A city that always (some claim) is too windy,
CHICAGO
a nightclub with theater, a place for a shindig,
the animals which are called Billy in Hindi.
This refers to
A German word meaning a cellar or basement,
KELLER
the husband of Marge in prime-time entertainment,
HOMER
with woman or one hit; a term of amazement.
WONDER
This refers to
HELEN
Deciduous trees used for veniks and vihtas,
BIRCH
the top-level domain for Indian tweeters,
IN
the most-spoken Germanic tongue with Norse features.
DANISH
This refers to
Altogether:
Number two With path or star; something that sparkles or lustres,
the first name of Trinity and Leia's actors,
CARRIE
distress just loves company despite all factors.
MISERY
This refers to
Both red and white ones are found inside the bloodstream,
CELLS
the ink on one's skin used to illustrate some theme,
TATTOO
the pope's Swiss ones are a protective escort team.
GUARD
This refers to
The MILITARY/POLICE?
A little naïve girl who gets herself eaten,
in 2007 World Series unbeaten,
BOSTON
the world's tallest trees are found nowhere near Eton.
REDWOOD?
This refers to
Altogether:
Number one An organ two of which you have close to your nose,
EYES
tall structure that's linked to no castles or châteaux,
TOWER
through Oxford and Reading this waterway outflows.
THAMES
This refers to
A term coined by More in his 1516 book,
UTOPIA (thanks, @deep thought!)
what black is to white and what hook is to unhook,
OPPOSITE
with tense or bright; forecasts predicting its outlook.
FUTURE
This refers to
DYSTOPIA, an opposite future Utopia.
In contrast to alien, a.k.a. Earthling,
between quid and quo, or professional's shortening,
PRO
in Genesis; making of something from nothing.
EVE
This refers to
Altogether: