The most simple way to avoid deadlock

Give an order number to each resource (table for example) and use them in every sp in the predefined order.

XML "database" with C#

1. Step: create class structure for dataset (I'll call it ADS)
2. Step: ADS ads = new ADS(); then init ads
3. Step: serialize

TextWriter writer = new StreamWriter("test.xml");
XmlSerializer serializer = new XmlSerializer(typeof(ADS));
serializer.Serialize(writer, ads);
writer.Close();

4. Step: delete serialize call
5. Step: start using the xml, read all your data in 5 (five) lines

XmlSerializer serializer = new XmlSerializer(typeof(ADS));
FileStream fs = new FileStream("test.xml", FileMode.Open);
XmlReader reader = new XmlTextReader(fs);
ads = (ADS)serializer.Deserialize(reader);
fs.Close();

PS. Don't forget about the try-catch(s), but throw all your oldschool ideas