Spread Recorder Robot - Write spread to text file

I've just created a simple robot to write spread to text file. We'll get some thing like this in text file when run this robot

13:20:10 | Bid:1.59871 | Ask:1.59902 | Spread:3.1
13:20:10 | Bid:1.59875 | Ask:1.59906 | Spread:3.1
13:20:11 | Bid:1.59872 | Ask:1.59902 | Spread:3
13:20:11 | Bid:1.59871 | Ask:1.59902 | Spread:3.1
13:20:12 | Bid:1.59875 | Ask:1.59906 | Spread:3.1
13:20:12 | Bid:1.59876 | Ask:1.59907 | Spread:3.1
13:20:14 | Bid:1.59877 | Ask:1.59908 | Spread:3.1
13:20:15 | Bid:1.59878 | Ask:1.59908 | Spread:3
13:20:15 | Bid:1.59879 | Ask:1.5991 | Spread:3.1
13:20:16 | Bid:1.59876 | Ask:1.59907 | Spread:3.1
13:20:17 | Bid:1.5987 | Ask:1.59901 | Spread:3.1
13:20:18 | Bid:1.5987 | Ask:1.59897 | Spread:2.7
13:20:19 | Bid:1.5987 | Ask:1.59899 | Spread:2.9
13:20:19 | Bid:1.59869 | Ask:1.59899 | Spread:3

Source code

using System;
using cAlgo.API;
using cAlgo.API.Indicators;
using cAlgo.Indicators;
using System.IO;
namespace cAlgo.Robots
{
    [Robot()]
    public class SpreadRecorder : Robot
    {
        StreamWriter _fileWriter;

        protected override void OnStart()
        {
            var desktopFolder = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory);
            var filePath = Path.Combine(desktopFolder, Symbol.Code + "-" + Server.Time.Year + "-" + Server.Time.Month + "-" + Server.Time.Day + "_Spread Record.txt");


            _fileWriter = File.AppendText(filePath);
            //creating file 
            _fileWriter.AutoFlush = true;
            //file will be saved on each change 
        }
        protected override void OnTick()
        {
            _fileWriter.WriteLine(Server.Time.Hour + ":" + Server.Time.Minute + ":" + Server.Time.Second + " | Bid:" + Symbol.Bid + " | Ask:" + Symbol.Ask + " | Spread:" + Math.Round(Symbol.Spread / Symbol.PipSize, 2));
        }
        protected override void OnStop()
        {
            _fileWriter.Close();
        }
    }
}

Can you help me with these questions:

1. This robot does not do any trading function. Should we use indicator instead of cbot? How to convert to Ctrader Indicator?

2. How do we set specific path for text file (ex: C\MyDocuments\... instead of Desktop)?

3. How do we get full digit (5 digits for most and 3 digits for XXX/JPY) for Bid and Ask data?

Ex: I want Ask data shows 1.59910 instead of 1.5991

3:20:15 | Bid:1.59878 | Ask:1.59908 | Spread:3
13:20:15 | Bid:1.59879 | Ask:1.5991 | Spread:3.1
13:20:16 | Bid:1.59876 | Ask:1.59907 | Spread:3.1