To answer your questions :
- the safari drive-thru, reptile house and large aviary closed before the park closure. From my visit last year and the infos on the website I understand these exhibits closed at 17h30 and the park at 19h30. But as
@Ned said you must start by the safari at the opening and enjoy it until it is too hot and crowded.
- yes there is a very good guidebook available in the park in french/english/spanish. The only matter is the price : 15 euros. But it's worth it !
- no sing-sing waterbucks at Sigean. They are not listed in the guidebook (2021) nor in this list from june 2022
Liste des animaux de la Réserve Africaine de Sigean - Nature et Zoo which you can trust.
- the same for eastern kiang but they left few years ago. For a time the park have them in a off-show plain only accessible with expensive VIP visit. But there are persian onagers in the past elephant enclosure.
- the talapoins were put in the large aviary at the end of last year but not sure they are still in as there were mistakes with the birds. Maybe they could be on-show in a smaller aviary near the larger one. You must open your eyes and ask staff if needed.
Do not miss the cuvier's gazelles in the pedestrian part. They are not on the main visitor path but just behind the hartmann moutain zebras and aoudads cliff.
I am quite sure you will enjoy your visit