Help with stateless firewall

Question

I am working with a stateless firewall to help keep up with DoS and a state flood. I have a few doubts about my setup:

a.) When allowing web traffic, is it necessary to allow port range 1000:65535 ? i saw that due to this rule sending packets to those ports directly respond with a REJECT instead of a DROP which is preferred. Any
work around and still have a stateless setup?

b.) What is needed to safely have a default OUTPUT DROP, apparently as soon as i change it to that iam unable to access it via ssh, even if I add a rule like this: /sbin/iptables -A OUTPUT -p tcp --dport 22 -j ACCEPT

#!/bin/bash

/sbin/iptables -F
/sbin/iptables -X

/sbin/iptables -P INPUT DROP
/sbin/iptables -P FORWARD DROP
/sbin/iptables -P OUTPUT ACCEPT

#ICMP IN
/sbin/iptables -A INPUT -p icmp -s 178.174.50.29/24 -j ACCEPT

#ICMP IN (TRACEROUTE)
/sbin/iptables -A INPUT -p icmp --icmp-type 0 -j ACCEPT
/sbin/iptables -A INPUT -p icmp --icmp-type 11 -j ACCEPT

#ICMP OUT
/sbin/iptables -A OUTPUT -p icmp --icmp-type 8 -j ACCEPT

#DNS RESOLVERS
/sbin/iptables -A INPUT -s 63.15.64.91 -j ACCEPT
/sbin/iptables -A INPUT -s 63.15.64.92 -j ACCEPT

#SSH
/sbin/iptables -A INPUT -p tcp --dport 22 -j ACCEPT

#WEB
/sbin/iptables -A INPUT -p tcp --dport 1000:65535 -j ACCEPT
/sbin/iptables -A INPUT -p tcp --dport 80 -j ACCEPT

Answer 1

What is a "state flood"? Why do you think a stateless firewall is superior, or even desirable?

a.) When allowing web traffic, is it neecessary to allow port range 1000:65535 ?

Regardless of the inbound port or protocol, for most, you *must* accept return traffic, or the connection cannot be made.

b.) What is needed to safely have a default OUTPUT DROP,

Rule of Thumb: If you need help to make it work, you do not need OUTPUT filtering. Just say No to DROP. :)

Why do you want OUTPUT DROP? What are you defending against? Generally a stronger and more effective defense against hostile system users would be something like SELinux. Another good idea:
don't give untrusted people shell access.