Who are the "Shomerim"?
Rashi: Nebuchadnetzar and his troops.
Seforno: "Sareha v'Kirbah Arayos Sho'agim..." (Tzefanyah 3:3).
Malbim (Melitzah): They are the powers that sustain bodily life. When she wanted to leave Chadrei Shlomo, i.e. separate from the body to influence of Nevu'ah, she could not pass them and deceive them like before. Now she was under their authority.
Malbim (Mashal): They guard the gate of the city.
Why do they go around the city?
Rashi: They take Hashem's vengeance.
Rashi (6): They catch thieves who go around at night
What is the meaning of "Hikuni Petza'uni"?
Rashi (6): They wounded me. Petza is a wound via a weapon.
Malbim (Melitzah): They forced the Nefesh to remain with its body, Midos and physical desires, until they returned it to its enclosure each time via lashes and wounds - illnesses of the Nefesh and its pains 1 .
Malbim: The Rambam (Shemoneh Perakim) says that the Nefesh has health and illness, just like the body.
What is "Redidi"?
Rashi: The Beis ha'Mikdash.
Rashi (6): My ornaments Merudad (flattened) on me.
Seforno: It is the contents of Eretz Yisrael - "va'Yavo'u va'Yochelu Eretz u'Melo'ah Ir v'Yoshvei Vah" (Yirmeyah 8:16).
Malbim (Melitzah): It is a head ornament. I.e. she was no longer able to gain understanding via Nevu'ah, without wall or barrier. Now she is limited to understanding of intellect tied to physicality, level by level.
Who are "Shomerei ha'Chomos"?
Rashi: It is even angels who guarded the walls - "Al Chomosayich Yerushalayim" (Yeshayah 62:6). They lit the fire - "mi'Marom Shalach Esh..." (Eichah 1:13).
Seforno: They are those who guard the city from the outside - "k'Shomerei Sadai Hayu Aleha mi'Saviv" (Yirmeyah 4:17).
Malbim (Melitzah): It is the body in which the Nefesh dwells.
