It's not necessarily the landlords that are the pain in the first instance - you'll find that agents can be quite manipulative and sneaky and, thus, set the precedent for the whole renting/moving experience.
One of the reasons that people have bad experiences is they have simply not prepared well enough. They don't spend anytime understanding the how the agent commission works here, they fail to research the
property sites, they get too emotionally attached to a place, and they don't negotiate and walk away if things get silly. It's almost the 'I've arrived in a new Country, this is a fresh start and I want to be everyone's mate' sort of syndrome. You wouldn't let people walk all over you in your home Country, so why let it happen here.
A corporate lease gives the landlord peace of mind that the rental will be paid consistently and on the same date each month. It is preferred by landlords but it can be a false sense of security in that a small company that isn't professional could quite easily default on the payments, and also where is the protection for the landlord if it goes bankrupt? A larger multinational has less probability of doing so etc.
For private owners, a surprising number are accommodating for cats. If its fully furnished you'll have to keep an eye on the scratching or you may have to replace damaged items. If you are furnishing it yourself, then its not so much an issue. Although with my cats, the curtains are their new play thing and they like to eat the blinds!!
To cover yourself take plenty of pictures when you take occupancy of areas that are likely to get damaged/experience wear and tear - such as entrances, furniture, work surfaces, oven etc. That way you have everything documented and if a dispute arises can prove otherwise or support your points. Keep all air con servicing invoices too and records for any work you had done. The usual cost level for work carried out at yor cost is below $150-200 dollars, above that threshold the landlord usually pays.
Try and speak to the landlord if you can and get a feel for how he/she is. Although this is not always possible as agents tend to be paranoid that you'll try and cut them out of any future deals.
In a nutshell, renting is expensive here in Singapore so it's worth putting some time into finding out exactly how the system works and potential banana skins. It's amazing how a lot of common sense goes out of the window because moving itself is a stressful thing, and people take agents at face value. If you are unsure of anything DO NOT sign anything until you have had chance to get a second opinion, and that doesn't include from the agent as all they tend to be interested in is getting the commission and then they couldn't give a sh*t about you.
Aim to have a checklist of things to do and make sure you try to follow it closely.
All the best!!