Adding more claimants - just clone an existing claimant, change the troop faction, and go to module_strings.py, and add an extra claimant string right after each Rhodok one. (it goes in numerical order)
For example:
["kingdom_5_pretender", "Lord Kastor of Veluca", "Kingdom 5 Lord", tf_hero|tf_unmoveable_in_party_window, 0,reserved, fac_kingdom_5,[itm_saddle_horse, itm_nobleman_outfit, itm_leather_boots, itm_splinted_leather_greaves, itm_mail_hauberk, itm_sword_medieval_c, itm_tab_shield_heater_d, itm_spiked_helmet], lord_attrib,wp(220),knows_lord_1, 0x0000000bed1031051da9abc49ecce25e00000000001e98680000000000000000, rhodok_face_old_2],
["kingdom_6_pretender", "Lord Blastor of Peluca", "Kingdom 5 Lord", tf_hero|tf_unmoveable_in_party_window, 0,reserved, fac_kingdom_6,[itm_saddle_horse, itm_nobleman_outfit, itm_leather_boots, itm_splinted_leather_greaves, itm_mail_hauberk, itm_sword_medieval_c, itm_tab_shield_heater_d, itm_spiked_helmet], lord_attrib,wp(220),knows_lord_1, 0x0000000bed1031051da9abc49ecce25e00000000001e98680000000000000000, rhodok_face_old_2],
module_strings:
("rhodok_rebellion_pretender_intro", "I am Lord Kastor, the rightful King of the Rhodoks, who will free them from tyranny."),
("kingdom_6_rebellion_pretender_intro", "I am Lord Flastor, the rightful King of the Crowdoks, who will free them from communism."),
("kingdom_7_rebellion_pretender_intro", "I am Lord Flastor, the rightful King of the Crowdoks, who will free them from communism."),
("rhodok_rebellion_monarch_response_1", "No doubt Lord Kastor told you that I defiled the hallowed Rhodok custom by interfering with the patricians' election of a king. Well, let me tell you something. The patricians of the towns make longwinded speeches about our ancient liberties, but then choose as their king whichever noble last sat in their villa and sipped a fine wine and promised to overlook their unpaid taxes."),
("kingdom_6_rebellion_monarch_response_1", "No doubt Lord Kastor told you that I defiled the hallowed Rhodok custom by interfering with the patricians' election of a king. Well, let me tell you something. The patricians of the towns make longwinded speeches about our ancient liberties, but then choose as their king whichever noble last sat in their villa and sipped a fine wine and promised to overlook their unpaid taxes."),
("kingdom_7_rebellion_monarch_response_1", "No doubt Lord Kastor told you that I defiled the hallowed Rhodok custom by interfering with the patricians' election of a king. Well, let me tell you something. The patricians of the towns make longwinded speeches about our ancient liberties, but then choose as their king whichever noble last sat in their villa and sipped a fine wine and promised to overlook their unpaid taxes."),
... and so on, do that for each claimant related string, remembering to put it in correct order according to number.
As for the NPC home areas; look for a line like this:
(troop_set_slot, "trp_npc8", slot_troop_home, "p_sea_raider_spawn_point_2"), #Gundig's Point
You can edit the talk in module_strings.py
("npc8_home_intro", "Hmf. Do you hear that? It must be the crash of waves on the headland. We must be near Gundig's Point."),
Hope that helps.