Hi Midas,
Safe2Travel do not do visa application for u unless u puchase the airtix or any packages with them. As for Chariot, if u're applying visa for at least 3 people.. they can charge u cheaper at $8/per pax. Bigger groups will be even cheaper. so u might wanna call & chk with them
As for transport, u can chk with the hotel if they provide free shuttle service from the airport, cos some of them do. Otherwise, just take the airport shuttle service. It's cheaper than taking a cab.
And yes, if u're bringing along any food items & medication, u need to declare them. Just tick on the appropriate item category in the declaration card will do.
As for exchange rate, if u're staying or working near Tanjong Pagar, u can chkout Perfect Exchange locted at Tanjong Pagar Plaza. It's just directly opp. Amara Hotel. Their rates are generally better than most other money changers, incl. those at The Arcade.